Document
false--12-31FY20180000750556YesfalseLarge Accelerated FilerSUNTRUST BANKS INCfalsefalseNoYes00.00530.006450.03860.031020.027860.04000.04000.056250.05050.0512560000000.980.0130000000.07840.050.340.00620.000.020.02150.0070.110.02500.010.220.00000.000.070.01640.0060.1234000000000001000000300000010000001000000110000000096500001.000.03690.02592028-01-152026-02-152028-03-152019-08-012026-11-022058-10-312026-05-152024-08-022043-12-192019-05-012026-02-152027-04-012019-08-012019-04-292019-01-162020-04-012021-01-292020-01-31000.15000.10000.70001.00000.40000.25000.05000.00000.50000.75000.20000.00000.060.060.01901.000.00410.410.01130.810.01651.000.00110.410.01080.8100.06000.06000.02500.06000.09550.05400.00690.03300.03440.02690.03290.02690.03150.010413000000100000002020000001700000012700000030000002600000026000000182000000154000000280000002020000001400000013000000001200000000520000001380000001000000117000000290000001170000001450000000210000001000001000001000001000000000P40YP20YP30YP5YP1YP1YP1YP1YP50YP20YP30YP5YP1YP1YP1YP1Y310000001.250.300.010.060.040.131.160.300.000.060.020.139.062264.5832P3YP3YIncludes noncontrolling interest of $103 million and $103 million at December?31, 2018 and December?31, 2017, respectively.Includes trading securities pledged as collateral where counterparties have the right to sell or repledge the collateral of $1,442 million and $1,086 million at December?31, 2018 and December?31, 2017, respectively.Beginning October 1, 2018, the Company reclassified software and related accumulated amortization previously presented in Other assets to Premises, property, and equipment, net. Reclassifications have been made to previously reported amounts for comparability.Includes restricted shares of 7 thousand and 9 thousand at December?31, 2018 and December?31, 2017, respectively.Beginning January 1, 2018, the Company reclassified equity securities previously presented in Securities available for sale to Other assets. Reclassifications have been made to previously reported amounts for comparability.Includes securities AFS pledged as collateral where counterparties have the right to sell or repledge the collateral of $222 million and $223 million at December?31, 2018 and December?31, 2017, respectively.Includes loans of consolidated VIEs of $153 million and $179 million at December?31, 2018 and December?31, 2017, respectively.Includes debt of consolidated VIEs of $161 million and $189 million at December?31, 2018 and December?31, 2017, respectively. 0000750556 2018-01-01 2018-12-31 0000750556 2018-06-29 0000750556 2019-02-15 0000750556 2018-12-31 0000750556 2016-01-01 2016-12-31 0000750556 2017-01-01 2017-12-31 0000750556 2017-12-31 0000750556 us-gaap:AvailableforsaleSecuritiesMember 2018-12-31 0000750556 us-gaap:RestrictedStockMember 2018-12-31 0000750556 us-gaap:AvailableforsaleSecuritiesMember 2017-12-31 0000750556 us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2017-12-31 0000750556 sti:TradingAssetsMember 2018-12-31 0000750556 us-gaap:RestrictedStockMember 2017-12-31 0000750556 sti:TradingAssetsMember 2017-12-31 0000750556 us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2018-12-31 0000750556 us-gaap:TreasuryStockMember 2018-12-31 0000750556 us-gaap:TreasuryStockMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2017-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2018-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2018-12-31 0000750556 us-gaap:RetainedEarningsMember 2018-01-01 2018-12-31 0000750556 us-gaap:TreasuryStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:PreferredStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-12-31 0000750556 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:AdditionalPaidInCapitalMember 2018-01-01 2018-12-31 0000750556 us-gaap:AdditionalPaidInCapitalMember 2017-01-01 2017-12-31 0000750556 us-gaap:CommonStockMember 2017-12-31 0000750556 us-gaap:TreasuryStockMember 2016-12-31 0000750556 2015-12-31 0000750556 us-gaap:CommonStockMember 2015-12-31 0000750556 us-gaap:AdditionalPaidInCapitalMember 2016-01-01 2016-12-31 0000750556 us-gaap:CommonStockMember 2018-12-31 0000750556 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-12-31 0000750556 us-gaap:RetainedEarningsMember 2015-12-31 0000750556 us-gaap:CommonStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:AdditionalPaidInCapitalMember 2017-12-31 0000750556 us-gaap:AdditionalPaidInCapitalMember 2016-12-31 0000750556 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:CommonStockMember 2016-12-31 0000750556 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2015-12-31 0000750556 us-gaap:CommonStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:CommonStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:TreasuryStockMember 2015-12-31 0000750556 us-gaap:TreasuryStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:RetainedEarningsMember 2017-01-01 2017-12-31 0000750556 us-gaap:TreasuryStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:PreferredStockMember 2017-12-31 0000750556 us-gaap:RetainedEarningsMember 2016-01-01 2016-12-31 0000750556 us-gaap:AdditionalPaidInCapitalMember 2015-12-31 0000750556 us-gaap:RetainedEarningsMember 2018-12-31 0000750556 us-gaap:RetainedEarningsMember 2017-12-31 0000750556 us-gaap:PreferredStockMember 2016-12-31 0000750556 us-gaap:AdditionalPaidInCapitalMember 2018-12-31 0000750556 us-gaap:PreferredStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:PreferredStockMember 2015-12-31 0000750556 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-12-31 0000750556 us-gaap:RetainedEarningsMember 2016-12-31 0000750556 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-01-01 2017-12-31 0000750556 2016-12-31 0000750556 us-gaap:PreferredStockMember 2018-12-31 0000750556 us-gaap:SeriesAPreferredStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:SeriesGPreferredStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:SeriesHPreferredStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesAPreferredStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesEPreferredStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:SeriesHPreferredStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:SeriesEPreferredStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesFPreferredStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:SeriesEPreferredStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:SeriesAPreferredStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:SeriesFPreferredStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesFPreferredStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:SeriesGPreferredStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesBPreferredStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesBPreferredStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:SeriesBPreferredStockMember 2017-01-01 2017-12-31 0000750556 sti:StrandedTaxEffectsinAOCIOffsetPortionMember 2018-01-01 2018-12-31 0000750556 sti:StrandedTaxEffectsinAOCINetPortionMember 2018-01-01 2018-12-31 0000750556 sti:ContingentConsiderationPaidinExcessofAcquisitionDateFairValueMemberMember 2016-01-01 2016-12-31 0000750556 sti:CashProceedsfromBOLICOLIMember 2018-01-01 2018-12-31 0000750556 sti:CashProceedsfromBOLICOLIMember 2017-01-01 2017-12-31 0000750556 sti:ContingentConsiderationPaidUptoAmountofAcquisitionDateFairValueMemberMember 2016-01-01 2016-12-31 0000750556 sti:CashPremiumsPaidonBOLICOLIMemberMember 2018-01-01 2018-12-31 0000750556 sti:ASU201409RevenuefromContractswithCustomersImpactonNoninterestExpenseDomain 2018-01-01 2018-12-31 0000750556 sti:AdoptionofASU201602Member 2018-12-31 0000750556 sti:CashProceedsfromBOLICOLIMember 2016-01-01 2016-12-31 0000750556 sti:CashPremiumsPaidonBOLICOLIMemberMember 2017-01-01 2017-12-31 0000750556 sti:ASU201409RevenuefromContractswithCustomersImpactonNoninterestIncomeDomain 2018-01-01 2018-12-31 0000750556 sti:StrandedTaxEffectsinAOCIGrossPortionMember 2018-01-01 2018-12-31 0000750556 sti:CashPremiumsPaidonBOLICOLIMemberMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:TradingMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:CommercialRealEstateMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member sti:InvestmentBankingMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:FiduciaryAndTrustMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:MortgageBankingMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:OtherIncomeMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FiduciaryAndTrustMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:NetSecuritiesGainsLossesMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member 2018-01-01 2018-12-31 0000750556 us-gaap:CreditAndDebitCardMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:FinancialServiceOtherMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FinancialServiceOtherMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member sti:NetSecuritiesGainsLossesMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:MortgageBankingMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 us-gaap:MortgageBankingMember 2018-01-01 2018-12-31 0000750556 us-gaap:DepositAccountMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member sti:TradingMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FinancialServiceOtherMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CommercialRealEstateMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 us-gaap:FinancialServiceOtherMember 2018-01-01 2018-12-31 0000750556 sti:TradingMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:CommercialRealEstateMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:DepositAccountMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:InvestmentBankingMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:DepositAccountMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CreditAndDebitCardMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:CreditAndDebitCardMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member sti:TradingMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:DepositAccountMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member sti:InvestmentBankingMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:OtherIncomeMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CommercialRealEstateMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member sti:NetSecuritiesGainsLossesMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:MortgageBankingMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member sti:NetSecuritiesGainsLossesMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FiduciaryAndTrustMember sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 us-gaap:FiduciaryAndTrustMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member sti:InvestmentBankingMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CreditAndDebitCardMember sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FinancialServiceOtherMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:SaleOfSubsidiaryGainLossMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:DepositAccountMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:NetSecuritiesGainsLossesMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CreditAndDebitCardMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member sti:NetSecuritiesGainsLossesMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:FinancialServiceOtherMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:TradingMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:MortgageBankingMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:SaleOfSubsidiaryGainLossMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 us-gaap:CreditAndDebitCardMember 2017-01-01 2017-12-31 0000750556 us-gaap:DepositAccountMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:DepositAccountMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:InvestmentBankingMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 us-gaap:MortgageBankingMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member 2017-01-01 2017-12-31 0000750556 us-gaap:CommercialRealEstateMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member sti:TradingMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:MortgageBankingMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:TradingMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:DepositAccountMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CommercialRealEstateMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:InvestmentBankingMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:OtherIncomeMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member sti:NetSecuritiesGainsLossesMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member sti:InvestmentBankingMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:MortgageBankingMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:OtherIncomeMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:SaleOfSubsidiaryGainLossMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CommercialRealEstateMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FiduciaryAndTrustMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FinancialServiceOtherMember sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:CreditAndDebitCardMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:CommercialRealEstateMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CreditAndDebitCardMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:NetSecuritiesGainsLossesMember 2017-01-01 2017-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FiduciaryAndTrustMember sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 us-gaap:FiduciaryAndTrustMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:FiduciaryAndTrustMember 2017-01-01 2017-12-31 0000750556 sti:TradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:FinancialServiceOtherMember 2017-01-01 2017-12-31 0000750556 sti:InvestmentBankingMember 2017-01-01 2017-12-31 0000750556 us-gaap:SaleOfSubsidiaryGainLossMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member sti:CorporateOtherMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member sti:CorporateOtherMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member sti:CorporateOtherMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:OutofScopeofASC606Member sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:OutofScopeofASC606Member sti:NetSecuritiesGainsLossesMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:InvestmentBankingMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:TradingMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:MortgageBankingMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:MortgageBankingMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember 2016-01-01 2016-12-31 0000750556 sti:InvestmentBankingMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:OtherIncomeMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CreditAndDebitCardMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:NetSecuritiesGainsLossesMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:OtherIncomeMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 us-gaap:FiduciaryAndTrustMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:TradingMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:NetSecuritiesGainsLossesMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:DepositAccountMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CommercialRealEstateMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:CreditAndDebitCardMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member sti:TradingMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:DepositAccountMember 2016-01-01 2016-12-31 0000750556 us-gaap:FinancialServiceOtherMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:FiduciaryAndTrustMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:CommercialRealEstateMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:InvestmentBankingMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 us-gaap:MortgageBankingMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FinancialServiceOtherMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CommercialRealEstateMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member sti:InvestmentBankingMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member sti:NetSecuritiesGainsLossesMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 us-gaap:DepositAccountMember 2016-01-01 2016-12-31 0000750556 us-gaap:CommercialRealEstateMember 2016-01-01 2016-12-31 0000750556 sti:TradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:CreditAndDebitCardMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FiduciaryAndTrustMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:DepositAccountMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:CreditAndDebitCardMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FiduciaryAndTrustMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:MortgageBankingMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:InvestmentAdvisoryManagementAndAdministrativeServiceMember sti:WholesaleMember 2016-01-01 2016-12-31 0000750556 sti:OutofScopeofASC606Member us-gaap:FinancialServiceOtherMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member us-gaap:FinancialServiceOtherMember sti:ConsumerMember 2016-01-01 2016-12-31 0000750556 sti:InScopeofASC606Member 2018-01-01 2018-12-31 0000750556 sti:PillarFinancialMember 2016-01-01 2016-12-31 0000750556 sti:PremiumAssignmentCorporationMember 2017-01-01 2017-12-31 0000750556 sti:PremiumAssignmentCorporationMember 2017-12-31 0000750556 sti:PremiumAssignmentCorporationMember 2016-01-01 2016-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:CommercialPaperMember 2017-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:CommercialPaperMember 2017-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:CommercialPaperMember 2017-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember 2018-12-31 0000750556 us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:CorporateDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityOvernightMember 2018-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:Maturity30To90DaysMember 2017-12-31 0000750556 us-gaap:CorporateDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember 2017-12-31 0000750556 us-gaap:Maturity30To90DaysMember 2018-12-31 0000750556 us-gaap:MaturityOvernightMember 2017-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:Maturity30To90DaysMember us-gaap:CorporateDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:CorporateDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:CorporateDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:MaturityUpTo30DaysMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:MaturityOvernightMember us-gaap:CommercialPaperMember 2017-12-31 0000750556 sti:TradingAssetsMember us-gaap:RepurchaseAgreementsMember 2018-12-31 0000750556 sti:TradingAssetsMember sti:EquityTradingMember 2018-12-31 0000750556 sti:TradingAssetsMember us-gaap:DerivativeMember 2017-12-31 0000750556 sti:TradingAssetsMember us-gaap:RepurchaseAgreementsMember 2017-12-31 0000750556 sti:TradingAssetsMember sti:EquityTradingMember 2017-12-31 0000750556 sti:TradingAssetsMember us-gaap:DerivativeMember 2018-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-12-31 0000750556 us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2017-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember 2017-12-31 0000750556 us-gaap:DerivativeFinancialInstrumentsAssetsMember 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember 2018-12-31 0000750556 us-gaap:DerivativeFinancialInstrumentsAssetsMember 2017-12-31 0000750556 us-gaap:LoansMember 2017-12-31 0000750556 us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2018-12-31 0000750556 us-gaap:LoansMember 2018-12-31 0000750556 us-gaap:OtherDebtSecuritiesMember sti:TemporarilyImpairedSecuritiesMember 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember sti:TemporarilyImpairedSecuritiesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember sti:TemporarilyImpairedSecuritiesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 sti:TemporarilyImpairedSecuritiesMember 2018-12-31 0000750556 sti:OtherThanTemporarilyImpairedSecuritiesMember 2018-12-31 0000750556 us-gaap:USTreasurySecuritiesMember sti:TemporarilyImpairedSecuritiesMember 2018-12-31 0000750556 us-gaap:USGovernmentAgenciesDebtSecuritiesMember sti:TemporarilyImpairedSecuritiesMember 2018-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember sti:TemporarilyImpairedSecuritiesMember 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember sti:TemporarilyImpairedSecuritiesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:OtherDebtSecuritiesMember sti:TemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 us-gaap:USGovernmentAgenciesDebtSecuritiesMember sti:TemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember sti:TemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember sti:TemporarilyImpairedSecuritiesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:USTreasurySecuritiesMember sti:TemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 sti:OtherThanTemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember sti:TemporarilyImpairedSecuritiesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 sti:TemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember sti:TemporarilyImpairedSecuritiesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember sti:TemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember sti:OtherThanTemporarilyImpairedSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:OtherDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:OtherDebtSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:USTreasurySecuritiesMember 2018-01-01 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember 2018-01-01 2018-12-31 0000750556 us-gaap:USTreasurySecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-01-01 2017-12-31 0000750556 us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-01-01 2018-12-31 0000750556 us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherDebtSecuritiesMember 2018-01-01 2018-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-01-01 2018-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2017-01-01 2017-12-31 0000750556 sti:ConsumerOtherDirectMember 2017-01-01 2017-12-31 0000750556 sti:CommercialandIndustrialMember 2017-01-01 2017-12-31 0000750556 sti:ConsumerIndirectMember 2017-01-01 2017-12-31 0000750556 us-gaap:HomeEquityMember 2017-01-01 2017-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2017-01-01 2017-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2018-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2017-12-31 0000750556 sti:ResidentialConstructionMember 2017-12-31 0000750556 sti:CommercialandIndustrialMember 2018-12-31 0000750556 sti:CommercialandIndustrialMember 2017-12-31 0000750556 sti:ResidentialConstructionMember 2018-12-31 0000750556 us-gaap:CommercialRealEstateMember 2018-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2017-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2018-12-31 0000750556 sti:ConsumerIndirectMember 2017-12-31 0000750556 sti:ConsumerIndirectMember 2018-12-31 0000750556 sti:ConsumerOtherDirectMember 2017-12-31 0000750556 us-gaap:HomeEquityMember 2017-12-31 0000750556 us-gaap:CommercialRealEstateMember 2017-12-31 0000750556 us-gaap:HomeEquityMember 2018-12-31 0000750556 sti:ConsumerOtherDirectMember 2018-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2018-12-31 0000750556 us-gaap:HomeEquityMember sti:FicoScoreBetween620And699Member 2018-12-31 0000750556 us-gaap:HomeEquityMember sti:FicoScoreBelow620Member 2018-12-31 0000750556 us-gaap:HomeEquityMember sti:FicoScore700AndAboveMember 2018-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember sti:FicoScoreBelow620Member 2017-12-31 0000750556 sti:ResidentialConstructionMember sti:FicoScoreBelow620Member 2017-12-31 0000750556 us-gaap:HomeEquityMember sti:FicoScoreBelow620Member 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember sti:FicoScore700AndAboveMember 2017-12-31 0000750556 sti:ResidentialConstructionMember sti:FicoScore700AndAboveMember 2018-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember sti:FicoScore700AndAboveMember 2018-12-31 0000750556 sti:ResidentialConstructionMember sti:FicoScoreBelow620Member 2018-12-31 0000750556 us-gaap:HomeEquityMember sti:FicoScoreBetween620And699Member 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember sti:FicoScoreBetween620And699Member 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember sti:FicoScoreBelow620Member 2018-12-31 0000750556 sti:ResidentialConstructionMember sti:FicoScore700AndAboveMember 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember sti:FicoScoreBetween620And699Member 2018-12-31 0000750556 sti:ResidentialConstructionMember sti:FicoScoreBetween620And699Member 2017-12-31 0000750556 sti:ResidentialConstructionMember sti:FicoScoreBetween620And699Member 2018-12-31 0000750556 us-gaap:HomeEquityMember sti:FicoScore700AndAboveMember 2017-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 sti:NonrecurringloanpurchaseMember us-gaap:ConsumerPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 sti:RecurringloanpurchaseMember us-gaap:ConsumerPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 sti:NonrecurringloanpurchaseMember us-gaap:ConsumerPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 sti:RecurringloanpurchaseMember us-gaap:ConsumerPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2017-01-01 2017-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:HomeEquityMember 2017-01-01 2017-12-31 0000750556 us-gaap:CommercialRealEstateMember 2016-01-01 2016-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:HomeEquityMember 2016-01-01 2016-12-31 0000750556 sti:CommercialandIndustrialMember 2018-01-01 2018-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2018-01-01 2018-12-31 0000750556 us-gaap:HomeEquityMember 2018-01-01 2018-12-31 0000750556 sti:ConsumerOtherDirectMember 2016-01-01 2016-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2016-01-01 2016-12-31 0000750556 us-gaap:CommercialRealEstateMember 2017-01-01 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2016-01-01 2016-12-31 0000750556 sti:ResidentialConstructionMember 2018-01-01 2018-12-31 0000750556 sti:ResidentialConstructionMember 2017-01-01 2017-12-31 0000750556 us-gaap:CommercialRealEstateMember 2018-01-01 2018-12-31 0000750556 sti:CommercialandIndustrialMember 2016-01-01 2016-12-31 0000750556 sti:ConsumerIndirectMember 2016-01-01 2016-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2016-01-01 2016-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2017-01-01 2017-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2018-01-01 2018-12-31 0000750556 sti:ConsumerOtherDirectMember 2018-01-01 2018-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 sti:ConsumerIndirectMember 2018-01-01 2018-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2016-01-01 2016-12-31 0000750556 sti:ConsumerIndirectMember 2017-01-01 2017-12-31 0000750556 sti:CommercialandIndustrialMember 2017-01-01 2017-12-31 0000750556 sti:ResidentialConstructionMember 2016-01-01 2016-12-31 0000750556 sti:ConsumerOtherDirectMember 2017-01-01 2017-12-31 0000750556 us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember 2017-12-31 0000750556 sti:CommercialConstructionMember 2017-12-31 0000750556 us-gaap:FederalFamilyEducationLoanProgramFfelpGuaranteedLoansMember 2017-12-31 0000750556 sti:CommercialConstructionMember 2018-12-31 0000750556 sti:CommercialConstructionMember us-gaap:PassMember 2017-12-31 0000750556 us-gaap:CommercialRealEstateMember sti:CriticizedAccruingMember 2018-12-31 0000750556 us-gaap:CommercialRealEstateMember sti:CriticizedAccruingMember 2017-12-31 0000750556 sti:CommercialConstructionMember sti:CriticizedAccruingMember 2018-12-31 0000750556 sti:CommercialConstructionMember us-gaap:PassMember 2018-12-31 0000750556 sti:CommercialandIndustrialMember us-gaap:PassMember 2017-12-31 0000750556 sti:CommercialConstructionMember sti:CriticizedAccruingMember 2017-12-31 0000750556 sti:CommercialandIndustrialMember us-gaap:PassMember 2018-12-31 0000750556 us-gaap:CommercialRealEstateMember us-gaap:PassMember 2017-12-31 0000750556 sti:CommercialandIndustrialMember sti:CriticizedAccruingMember 2018-12-31 0000750556 sti:CommercialandIndustrialMember sti:CriticizedAccruingMember 2017-12-31 0000750556 us-gaap:CommercialRealEstateMember us-gaap:PassMember 2018-12-31 0000750556 us-gaap:FederalNationalMortgageAssociationFnmaInsuredLoansMember 2018-12-31 0000750556 us-gaap:FederalFamilyEducationLoanProgramFfelpGuaranteedLoansMember 2018-12-31 0000750556 us-gaap:HomeEquityMember 2018-01-01 2018-12-31 0000750556 sti:ResidentialConstructionMember 2018-01-01 2018-12-31 0000750556 us-gaap:CommercialRealEstateMember 2018-01-01 2018-12-31 0000750556 sti:CommercialandIndustrialMember 2018-01-01 2018-12-31 0000750556 sti:ConsumerOtherDirectMember 2018-01-01 2018-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2018-01-01 2018-12-31 0000750556 sti:ConsumerIndirectMember 2018-01-01 2018-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2018-01-01 2018-12-31 0000750556 sti:ResidentialMortgageInterestOnlyLoansMember 2018-12-31 0000750556 sti:InterestOnlyMortgagewithnoMIandwithCombinedOriginalLTVgreaterthan80Member sti:ResidentialMortgageInterestOnlyLoansMember 2017-12-31 0000750556 sti:InterestOnlyMortgagewithnoMIandwithCombinedOriginalLTVgreaterthan80Member sti:ResidentialMortgageInterestOnlyLoansMember 2018-12-31 0000750556 sti:InterestOnlyMortgagewithMIorwithCombinedOriginalLTVlessthan80Member sti:ResidentialMortgageInterestOnlyLoansMember 2018-12-31 0000750556 sti:ResidentialMortgageAmortizingLoansMember 2017-12-31 0000750556 sti:InterestOnlyMortgagewithMIorwithCombinedOriginalLTVlessthan80Member sti:ResidentialMortgageInterestOnlyLoansMember 2017-12-31 0000750556 sti:ResidentialMortgageInterestOnlyLoansMember 2017-12-31 0000750556 sti:ResidentialMortgageAmortizingLoansMember 2018-12-31 0000750556 us-gaap:CreditCardReceivablesMember sti:FicoScoreBetween620And699Member 2017-12-31 0000750556 us-gaap:CreditCardReceivablesMember sti:FicoScoreBelow620Member 2017-12-31 0000750556 sti:ConsumerIndirectMember sti:FicoScoreBelow620Member 2017-12-31 0000750556 us-gaap:CreditCardReceivablesMember sti:FicoScoreBetween620And699Member 2018-12-31 0000750556 sti:ConsumerOtherDirectMember sti:FicoScoreBelow620Member 2018-12-31 0000750556 sti:ConsumerIndirectMember sti:FicoScoreBelow620Member 2018-12-31 0000750556 sti:ConsumerIndirectMember sti:FicoScoreBetween620And699Member 2017-12-31 0000750556 sti:ConsumerOtherDirectMember sti:FicoScoreBelow620Member 2017-12-31 0000750556 us-gaap:CreditCardReceivablesMember sti:FicoScore700AndAboveMember 2017-12-31 0000750556 sti:ConsumerIndirectMember sti:FicoScoreBetween620And699Member 2018-12-31 0000750556 sti:ConsumerOtherDirectMember sti:FicoScore700AndAboveMember 2017-12-31 0000750556 us-gaap:CreditCardReceivablesMember sti:FicoScoreBelow620Member 2018-12-31 0000750556 sti:ConsumerOtherDirectMember sti:FicoScoreBetween620And699Member 2017-12-31 0000750556 sti:ConsumerOtherDirectMember sti:FicoScoreBetween620And699Member 2018-12-31 0000750556 sti:ConsumerIndirectMember sti:FicoScore700AndAboveMember 2017-12-31 0000750556 us-gaap:CreditCardReceivablesMember sti:FicoScore700AndAboveMember 2018-12-31 0000750556 sti:ConsumerIndirectMember sti:FicoScore700AndAboveMember 2018-12-31 0000750556 sti:ConsumerOtherDirectMember sti:FicoScore700AndAboveMember 2018-12-31 0000750556 us-gaap:LandAndLandImprovementsMember 2018-12-31 0000750556 sti:ProceedsduefromFHAorVAMember 2018-12-31 0000750556 us-gaap:ResidentialPortfolioSegmentMember 2017-12-31 0000750556 us-gaap:FederalReserveBankAdvancesMember 2017-12-31 0000750556 sti:AccrualLoansMember 2017-12-31 0000750556 us-gaap:FederalHomeLoanBankAdvancesMember 2017-12-31 0000750556 us-gaap:FederalHomeLoanBankAdvancesMember 2017-12-31 0000750556 us-gaap:FederalHomeLoanBankAdvancesMember 2018-12-31 0000750556 us-gaap:ResidentialPortfolioSegmentMember 2018-12-31 0000750556 us-gaap:FinanceLeasesPortfolioSegmentMember 2017-12-31 0000750556 us-gaap:FederalHomeLoanBankAdvancesMember 2018-12-31 0000750556 us-gaap:CreditConcentrationRiskMember us-gaap:MortgagesMember 2018-12-31 0000750556 sti:InstallmentLoansMember 2017-12-31 0000750556 us-gaap:CreditConcentrationRiskMember us-gaap:HomeEquityMember 2017-12-31 0000750556 sti:NonaccrualloansMember 2017-12-31 0000750556 us-gaap:GeographicDistributionForeignMember 2018-12-31 0000750556 us-gaap:FinanceLeasesPortfolioSegmentMember 2018-12-31 0000750556 us-gaap:CreditConcentrationRiskMember us-gaap:MortgagesMember 2017-12-31 0000750556 sti:AccrualLoansMember 2018-12-31 0000750556 srt:MinimumMember us-gaap:CommercialPortfolioSegmentMember 2018-12-31 0000750556 sti:ProceedsduefromFHAorVAMember 2017-12-31 0000750556 us-gaap:FederalReserveBankAdvancesMember 2018-12-31 0000750556 us-gaap:GeographicDistributionForeignMember 2017-12-31 0000750556 us-gaap:CreditConcentrationRiskMember us-gaap:HomeEquityMember 2018-12-31 0000750556 sti:NonaccrualloansMember 2018-12-31 0000750556 sti:InstallmentLoansMember 2018-12-31 0000750556 us-gaap:LandAndLandImprovementsMember 2017-12-31 0000750556 sti:ConsumerOtherDirectMember 2016-01-01 2016-12-31 0000750556 sti:ResidentialConstructionMember 2016-01-01 2016-12-31 0000750556 sti:ResidentialMortgagesNonguaranteedMember 2016-01-01 2016-12-31 0000750556 us-gaap:CreditCardReceivablesMember 2016-01-01 2016-12-31 0000750556 sti:ConsumerIndirectMember 2016-01-01 2016-12-31 0000750556 sti:CommercialConstructionMember 2016-01-01 2016-12-31 0000750556 us-gaap:HomeEquityMember 2016-01-01 2016-12-31 0000750556 sti:CommercialandIndustrialMember 2016-01-01 2016-12-31 0000750556 srt:MinimumMember us-gaap:CommercialPortfolioSegmentMember 2017-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2015-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2016-12-31 0000750556 us-gaap:CommercialPortfolioSegmentMember 2016-12-31 0000750556 us-gaap:ConsumerPortfolioSegmentMember 2015-12-31 0000750556 srt:MaximumMember us-gaap:LeaseholdImprovementsMember 2018-01-01 2018-12-31 0000750556 srt:MaximumMember us-gaap:SoftwareAndSoftwareDevelopmentCostsMember 2018-01-01 2018-12-31 0000750556 srt:MinimumMember us-gaap:LeaseholdImprovementsMember 2017-01-01 2017-12-31 0000750556 srt:MinimumMember us-gaap:BuildingAndBuildingImprovementsMember 2017-01-01 2017-12-31 0000750556 srt:MinimumMember us-gaap:FurnitureAndFixturesMember 2018-01-01 2018-12-31 0000750556 srt:MinimumMember us-gaap:SoftwareAndSoftwareDevelopmentCostsMember 2017-01-01 2017-12-31 0000750556 srt:MaximumMember us-gaap:FurnitureAndFixturesMember 2017-01-01 2017-12-31 0000750556 srt:MinimumMember us-gaap:SoftwareAndSoftwareDevelopmentCostsMember 2018-01-01 2018-12-31 0000750556 srt:MaximumMember us-gaap:FurnitureAndFixturesMember 2018-01-01 2018-12-31 0000750556 srt:MaximumMember us-gaap:BuildingAndBuildingImprovementsMember 2018-01-01 2018-12-31 0000750556 srt:MinimumMember us-gaap:BuildingAndBuildingImprovementsMember 2018-01-01 2018-12-31 0000750556 srt:MinimumMember us-gaap:FurnitureAndFixturesMember 2017-01-01 2017-12-31 0000750556 srt:MaximumMember us-gaap:BuildingAndBuildingImprovementsMember 2017-01-01 2017-12-31 0000750556 srt:MinimumMember us-gaap:LeaseholdImprovementsMember 2018-01-01 2018-12-31 0000750556 srt:MaximumMember us-gaap:LeaseholdImprovementsMember 2017-01-01 2017-12-31 0000750556 srt:MaximumMember us-gaap:SoftwareAndSoftwareDevelopmentCostsMember 2017-01-01 2017-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2016-01-01 2016-12-31 0000750556 sti:PillarFinancialMember 2018-01-01 2018-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2017-01-01 2017-12-31 0000750556 sti:PillarFinancialMember 2016-01-01 2016-12-31 0000750556 sti:PillarFinancialMember 2017-01-01 2017-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2018-01-01 2018-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2017-01-01 2017-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2017-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2018-01-01 2018-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2018-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2016-01-01 2016-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2018-01-01 2018-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2017-01-01 2017-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2018-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2017-12-31 0000750556 sti:ConsumerMember 2018-01-01 2018-12-31 0000750556 sti:PillarFinancialMember 2017-12-31 0000750556 sti:PillarFinancialMember 2018-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2017-12-31 0000750556 us-gaap:OtherIntangibleAssetsMember 2017-12-31 0000750556 us-gaap:OtherIntangibleAssetsMember 2018-12-31 0000750556 us-gaap:OtherIntangibleAssetsMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherIntangibleAssetsMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherIntangibleAssetsMember 2016-12-31 0000750556 sti:MortgageServicingRightsFairValueMember 2016-12-31 0000750556 sti:WholesaleMember 2016-12-31 0000750556 sti:WholesaleMember 2018-12-31 0000750556 sti:WholesaleMember 2017-12-31 0000750556 sti:ConsumerMember 2018-12-31 0000750556 sti:ConsumerMember 2017-01-01 2017-12-31 0000750556 sti:WholesaleMember 2018-01-01 2018-12-31 0000750556 sti:ConsumerMember 2017-12-31 0000750556 sti:WholesaleMember 2017-01-01 2017-12-31 0000750556 sti:ConsumerMember 2016-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2017-01-01 2017-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2018-01-01 2018-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2017-12-31 0000750556 sti:CommercialMortgageServicingRightsMember 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember 2018-01-01 2018-12-31 0000750556 sti:TaxCreditInvestmentsMember 2017-12-31 0000750556 sti:TaxCreditInvestmentsMember 2018-12-31 0000750556 sti:StudentLoansMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2017-12-31 0000750556 us-gaap:LimitedPartnerMember sti:CommunityDevelopmentInvestmentsMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2018-12-31 0000750556 sti:STISponsoredSecuritizationsMember us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2017-12-31 0000750556 sti:ManagedSecuritizedLoansMember us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2018-12-31 0000750556 us-gaap:TotalReturnSwapMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2018-12-31 0000750556 us-gaap:LimitedPartnerMember sti:CommunityDevelopmentInvestmentsMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2017-12-31 0000750556 us-gaap:TotalReturnSwapMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2017-12-31 0000750556 us-gaap:ResidentialMortgageMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2016-01-01 2016-12-31 0000750556 sti:StudentLoansMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2018-12-31 0000750556 sti:ManagedSecuritizedLoansMember us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2017-12-31 0000750556 srt:MaximumMember sti:StudentLoansMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2018-12-31 0000750556 sti:CommercialAndCorporateLoansMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2018-01-01 2018-12-31 0000750556 us-gaap:ResidentialMortgageMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2017-01-01 2017-12-31 0000750556 sti:STISponsoredSecuritizationsMember us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2018-12-31 0000750556 sti:CommercialAndCorporateLoansMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2017-01-01 2017-12-31 0000750556 srt:MaximumMember sti:DeathDisabilityBankruptcyMember sti:StudentLoansMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2018-12-31 0000750556 us-gaap:ResidentialMortgageMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2017-12-31 0000750556 us-gaap:LimitedPartnerMember us-gaap:RenewableEnergyProgramMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2018-12-31 0000750556 us-gaap:ResidentialMortgageMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2018-01-01 2018-12-31 0000750556 us-gaap:RenewableEnergyProgramMember 2018-12-31 0000750556 sti:CommunityDevelopmentInvestmentsMember 2017-12-31 0000750556 us-gaap:RenewableEnergyProgramMember 2017-12-31 0000750556 us-gaap:LimitedPartnerMember us-gaap:RenewableEnergyProgramMember us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2017-12-31 0000750556 sti:CommunityDevelopmentInvestmentsMember 2018-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2018-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:CommercialPortfolioSegmentMember 2018-12-31 0000750556 us-gaap:LoansAndFinanceReceivablesMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:LoansAndFinanceReceivablesMember 2018-12-31 0000750556 us-gaap:LoansMember 2018-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:ConsumerPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:CommercialPortfolioSegmentMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember 2018-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember 2017-01-01 2017-12-31 0000750556 us-gaap:LoansMember 2017-12-31 0000750556 us-gaap:LoansMember 2017-01-01 2017-12-31 0000750556 us-gaap:LoansAndFinanceReceivablesMember 2017-01-01 2017-12-31 0000750556 us-gaap:LoansAndFinanceReceivablesMember 2018-01-01 2018-12-31 0000750556 us-gaap:LoansMember 2018-01-01 2018-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember 2018-01-01 2018-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:CommercialPortfolioSegmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:AssetBackedSecuritiesSecuritizedLoansAndReceivablesMember us-gaap:CommercialPortfolioSegmentMember 2017-01-01 2017-12-31 0000750556 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2017-01-01 2017-12-31 0000750556 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2018-01-01 2018-12-31 0000750556 us-gaap:VariableInterestEntityNotPrimaryBeneficiaryMember 2016-01-01 2016-12-31 0000750556 srt:MaximumMember sti:StudentLoansMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2017-12-31 0000750556 2018-10-01 2018-12-31 0000750556 srt:SubsidiariesMember 2018-12-31 0000750556 srt:ParentCompanyMember 2018-12-31 0000750556 sti:ConsumerandothertimeMember 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 sti:NextTwelveMonthsMember 2018-12-31 0000750556 sti:YearTwoMember 2018-12-31 0000750556 sti:YearThreeMember 2018-12-31 0000750556 sti:AfterYearFiveMember 2018-12-31 0000750556 sti:YearFourMember 2018-12-31 0000750556 sti:YearFiveMember 2018-12-31 0000750556 srt:SubsidiariesMember sti:A5YearsMember sti:FixedInterestRateDebtMember us-gaap:SeniorNotesMember 2018-01-01 2018-03-31 0000750556 srt:SubsidiariesMember sti:A6YearsMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-07-01 2018-09-30 0000750556 srt:SubsidiariesMember sti:A3YearsMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-10-01 2018-12-31 0000750556 srt:SubsidiariesMember sti:A7YearsMember sti:FixedInterestRateDebtMember us-gaap:SeniorNotesMember 2018-10-01 2018-12-31 0000750556 srt:SubsidiariesMember sti:A4YearsMember sti:FloatingInterestRateDebtMember us-gaap:SeniorNotesMember 2018-07-01 2018-09-30 0000750556 srt:SubsidiariesMember sti:A3YearsMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-01-01 2018-03-31 0000750556 srt:ParentCompanyMember sti:A7YearsMember sti:FixedInterestRateDebtMember us-gaap:SeniorNotesMember 2018-04-01 2018-06-30 0000750556 srt:SubsidiariesMember sti:A4YearsMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-07-01 2018-09-30 0000750556 srt:SubsidiariesMember sti:A3YearsMember sti:FloatingInterestRateDebtMember us-gaap:SeniorNotesMember 2018-10-01 2018-12-31 0000750556 sti:MasterNotesMember 2018-12-31 0000750556 us-gaap:FederalHomeLoanBankAdvancesMember 2017-12-31 0000750556 sti:MasterNotesMember 2017-12-31 0000750556 sti:OtherShortTermBorrowingsMember 2017-12-31 0000750556 sti:DealerCollateralMember 2017-12-31 0000750556 us-gaap:SecuritiesSoldUnderAgreementsToRepurchaseMember 2018-12-31 0000750556 sti:DealerCollateralMember 2018-12-31 0000750556 us-gaap:FederalHomeLoanBankAdvancesMember 2018-12-31 0000750556 us-gaap:SecuritiesSoldUnderAgreementsToRepurchaseMember 2017-12-31 0000750556 sti:OtherShortTermBorrowingsMember 2018-12-31 0000750556 us-gaap:FederalFundsPurchasedMember 2017-12-31 0000750556 us-gaap:FederalFundsPurchasedMember 2018-12-31 0000750556 sti:FinanceLeasesMember 2018-01-01 2018-12-31 0000750556 sti:TiertworiskbasedcapitalMember 2018-12-31 0000750556 sti:TiertworiskbasedcapitalMember 2017-12-31 0000750556 us-gaap:FederalHomeLoanBankAdvancesMember 2018-01-01 2018-12-31 0000750556 sti:DebtdenominatedinforeigncurrencyMember 2018-12-31 0000750556 srt:ParentCompanyMember us-gaap:StructuredFinanceMember 2018-12-31 0000750556 srt:ParentCompanyMember us-gaap:SeniorNotesMember 2017-12-31 0000750556 srt:SubsidiariesMember 2017-12-31 0000750556 srt:ParentCompanyMember us-gaap:JuniorSubordinatedDebtMember 2018-12-31 0000750556 srt:ParentCompanyMember us-gaap:SubordinatedDebtMember 2017-12-31 0000750556 srt:ParentCompanyMember 2017-12-31 0000750556 srt:SubsidiariesMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2017-12-31 0000750556 srt:SubsidiariesMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:SubsidiariesMember us-gaap:SubordinatedDebtMember 2018-12-31 0000750556 srt:SubsidiariesMember us-gaap:SubordinatedDebtMember 2017-12-31 0000750556 srt:ParentCompanyMember us-gaap:SubordinatedDebtMember 2018-12-31 0000750556 srt:SubsidiariesMember us-gaap:SeniorNotesMember 2017-12-31 0000750556 srt:ParentCompanyMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:ParentCompanyMember us-gaap:JuniorSubordinatedDebtMember 2017-12-31 0000750556 srt:SubsidiariesMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:ParentCompanyMember us-gaap:StructuredFinanceMember 2017-12-31 0000750556 sti:DebtdenominatedinforeigncurrencyMember 2017-12-31 0000750556 srt:SubsidiariesMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-01-01 2018-12-31 0000750556 srt:SubsidiariesMember sti:FloatingInterestRateDebtMember us-gaap:SeniorNotesMember 2018-01-01 2018-12-31 0000750556 srt:ParentCompanyMember us-gaap:StructuredFinanceMember 2018-01-01 2018-12-31 0000750556 srt:SubsidiariesMember srt:MaximumMember us-gaap:SubordinatedDebtMember 2018-12-31 0000750556 srt:ParentCompanyMember srt:MaximumMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:ParentCompanyMember sti:FixedInterestRateDebtMember us-gaap:SeniorNotesMember 2018-01-01 2018-12-31 0000750556 srt:SubsidiariesMember sti:FixedInterestRateDebtMember us-gaap:SubordinatedDebtMember 2018-01-01 2018-12-31 0000750556 srt:ParentCompanyMember sti:FixedInterestRateDebtMember us-gaap:SubordinatedDebtMember 2018-01-01 2018-12-31 0000750556 srt:ParentCompanyMember srt:MaximumMember us-gaap:JuniorSubordinatedDebtMember 2018-12-31 0000750556 srt:ParentCompanyMember srt:MinimumMember us-gaap:JuniorSubordinatedDebtMember 2018-12-31 0000750556 srt:SubsidiariesMember srt:MaximumMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:SubsidiariesMember sti:FixedInterestRateDebtMember us-gaap:SeniorNotesMember 2018-01-01 2018-12-31 0000750556 srt:SubsidiariesMember srt:MaximumMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:SubsidiariesMember srt:MinimumMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:ParentCompanyMember srt:MinimumMember us-gaap:SubordinatedDebtMember 2018-12-31 0000750556 srt:ParentCompanyMember sti:FloatingInterestRateDebtMember us-gaap:SeniorNotesMember 2018-01-01 2018-12-31 0000750556 srt:ParentCompanyMember srt:MinimumMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 srt:SubsidiariesMember srt:MinimumMember us-gaap:SubordinatedDebtMember 2018-12-31 0000750556 srt:ParentCompanyMember sti:FloatingInterestRateDebtMember us-gaap:JuniorSubordinatedDebtMember 2018-01-01 2018-12-31 0000750556 srt:ParentCompanyMember srt:MaximumMember us-gaap:SubordinatedDebtMember 2018-12-31 0000750556 srt:SubsidiariesMember srt:MinimumMember sti:FixedtoFloatingRateDebtMember us-gaap:SeniorNotesMember 2018-12-31 0000750556 sti:WarrantsoptionsandrestrictedstockMember 2017-01-01 2017-12-31 0000750556 sti:WarrantsoptionsandrestrictedstockMember 2016-01-01 2016-12-31 0000750556 us-gaap:RestrictedStockUnitsRSUMember 2016-01-01 2016-12-31 0000750556 sti:WarrantsoptionsandrestrictedstockMember 2018-01-01 2018-12-31 0000750556 us-gaap:RestrictedStockUnitsRSUMember 2017-01-01 2017-12-31 0000750556 us-gaap:RestrictedStockUnitsRSUMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesBMember 2017-01-01 2017-12-31 0000750556 us-gaap:SeriesCPreferredStockMember 2008-12-31 0000750556 us-gaap:CommonStockMember 2018-01-01 2018-06-30 0000750556 2018-01-01 2018-09-30 0000750556 2018-01-01 2018-06-30 0000750556 us-gaap:SeriesAMember 2008-12-31 0000750556 srt:MinimumMember 2018-12-31 0000750556 us-gaap:SeriesBMember 2008-12-31 0000750556 us-gaap:CommonStockMember 2018-12-31 0000750556 us-gaap:SeriesAMember 2011-09-22 0000750556 us-gaap:CommonStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:SeriesAPreferredStockMember 2006-09-30 0000750556 us-gaap:WarrantMember 2008-12-31 0000750556 us-gaap:SeriesAMember 2017-01-01 2017-12-31 0000750556 us-gaap:SeriesDPreferredStockMember 2008-12-31 0000750556 sti:SunTrustBankMember 2018-12-31 0000750556 sti:SunTrustBankMember 2017-12-31 0000750556 us-gaap:SeriesHPreferredStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:SeriesGPreferredStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:SeriesAPreferredStockMember 2016-12-31 0000750556 us-gaap:SeriesFPreferredStockMember 2016-12-31 0000750556 us-gaap:SeriesHPreferredStockMember 2018-12-31 0000750556 us-gaap:SeriesFPreferredStockMember 2017-12-31 0000750556 us-gaap:SeriesBPreferredStockMember 2016-12-31 0000750556 us-gaap:SeriesGPreferredStockMember 2016-12-31 0000750556 us-gaap:SeriesBPreferredStockMember 2017-12-31 0000750556 us-gaap:SeriesEPreferredStockMember 2018-12-31 0000750556 us-gaap:SeriesAPreferredStockMember 2017-12-31 0000750556 us-gaap:SeriesHPreferredStockMember 2017-12-31 0000750556 us-gaap:SeriesGPreferredStockMember 2017-12-31 0000750556 us-gaap:SeriesHPreferredStockMember 2016-12-31 0000750556 us-gaap:SeriesAPreferredStockMember 2018-12-31 0000750556 us-gaap:SeriesFPreferredStockMember 2018-12-31 0000750556 us-gaap:SeriesBPreferredStockMember 2018-12-31 0000750556 us-gaap:SeriesEPreferredStockMember 2017-12-31 0000750556 us-gaap:SeriesGPreferredStockMember 2018-12-31 0000750556 us-gaap:SeriesEPreferredStockMember 2016-12-31 0000750556 us-gaap:SeriesHPreferredStockMember 2017-11-30 0000750556 us-gaap:SeriesFPreferredStockMember 2014-11-30 0000750556 us-gaap:SeriesBPreferredStockMember 2011-12-31 0000750556 us-gaap:SeriesGPreferredStockMember 2017-05-31 0000750556 us-gaap:InvestmentsMember 2018-01-01 2018-12-31 0000750556 us-gaap:InvestmentsMember 2016-01-01 2016-12-31 0000750556 us-gaap:InvestmentsMember 2017-01-01 2017-12-31 0000750556 us-gaap:AdjustmentsForNewAccountingPrincipleEarlyAdoptionMember 2016-01-01 2016-12-31 0000750556 us-gaap:AdjustmentsForNewAccountingPrincipleEarlyAdoptionMember 2017-01-01 2017-12-31 0000750556 us-gaap:AdjustmentsForNewAccountingPrincipleEarlyAdoptionMember 2018-01-01 2018-12-31 0000750556 sti:FederalandStateMember 2018-01-01 2018-12-31 0000750556 sti:FederalandStateMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel3Member 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:MoneyMarketFundsMember 2018-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member 2018-12-31 0000750556 us-gaap:DerivativeMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:DerivativeMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member 2018-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:DerivativeMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:DerivativeMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member 2018-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel2Member 2018-12-31 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel1Member 2018-12-31 0000750556 us-gaap:RestrictedStockMember 2016-01-01 2016-12-31 0000750556 us-gaap:RestrictedStockMember 2017-01-01 2017-12-31 0000750556 us-gaap:RestrictedStockMember 2018-01-01 2018-12-31 0000750556 us-gaap:RestrictedStockUnitsRSUMember 2017-12-31 0000750556 us-gaap:RestrictedStockMember 2017-12-31 0000750556 us-gaap:RestrictedStockUnitsRSUMember 2018-12-31 0000750556 us-gaap:RestrictedStockMember 2018-12-31 0000750556 us-gaap:PensionPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-01-01 2017-12-31 0000750556 us-gaap:PensionPlansDefinedBenefitMember 2016-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-01-01 2018-12-31 0000750556 us-gaap:PensionPlansDefinedBenefitMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2016-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap:MarketApproachValuationTechniqueMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember us-gaap:MarketApproachValuationTechniqueMember 2017-01-01 2017-12-31 0000750556 us-gaap:PensionPlansDefinedBenefitMember 2016-01-01 2016-12-31 0000750556 us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2016-01-01 2016-12-31 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 sti:LongtermMember 2016-01-01 2016-12-31 0000750556 2018-04-24 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 sti:ShorttermMember 2017-01-01 2017-12-31 0000750556 sti:LongtermMember 2017-01-01 2017-12-31 0000750556 sti:ShorttermMember 2018-01-01 2018-12-31 0000750556 sti:ShorttermMember 2016-01-01 2016-12-31 0000750556 sti:LongtermMember 2018-01-01 2018-12-31 0000750556 sti:PlanParticipantsMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 sti:PlanTrustsMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 sti:PlanTrustsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 sti:PlanParticipantsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 sti:Range1Member 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:DebtSecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:CashEquivalentsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:DebtSecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:CashEquivalentsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:CashEquivalentsMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:CashEquivalentsMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:DebtSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:DebtSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:DerivativeMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:DerivativeMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel1Member 2017-12-31 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel2Member 2017-12-31 0000750556 us-gaap:MoneyMarketFundsMember us-gaap:FairValueInputsLevel3Member 2017-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:FairValueInputsLevel1Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member 2017-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member 2017-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:FairValueInputsLevel1Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:MoneyMarketFundsMember 2017-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:DerivativeMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FixedIncomeSecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:NontaxableMunicipalBondsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:FixedIncomeFundsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:FairValueInputsLevel2Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel2Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:EquitySecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:DerivativeMember us-gaap:PensionPlansDefinedBenefitMember 2017-12-31 0000750556 us-gaap:EquityFundsMember us-gaap:FairValueInputsLevel3Member us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2017-12-31 0000750556 srt:MinimumMember us-gaap:DebtSecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MaximumMember us-gaap:DebtSecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MaximumMember us-gaap:CashEquivalentsMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MinimumMember us-gaap:EquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 sti:Range1Member 2018-01-01 2018-12-31 0000750556 srt:MaximumMember us-gaap:EquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MinimumMember us-gaap:DebtSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MaximumMember us-gaap:CashEquivalentsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MinimumMember us-gaap:EquitySecuritiesMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MaximumMember us-gaap:EquitySecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MaximumMember us-gaap:DebtSecuritiesMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MinimumMember us-gaap:CashEquivalentsMember us-gaap:PensionPlansDefinedBenefitMember 2018-12-31 0000750556 srt:MinimumMember us-gaap:CashEquivalentsMember us-gaap:OtherPostretirementBenefitPlansDefinedBenefitMember 2018-12-31 0000750556 us-gaap:GuaranteeOfIndebtednessOfOthersMember 2017-12-31 0000750556 sti:VisaInterestMember 2018-12-31 0000750556 us-gaap:StandbyLettersOfCreditMember 2017-12-31 0000750556 us-gaap:GuaranteeOfIndebtednessOfOthersMember 2018-12-31 0000750556 us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember sti:VisaInterestMember us-gaap:NondesignatedMember 2009-05-01 2009-05-31 0000750556 us-gaap:StandbyLettersOfCreditMember 2018-12-31 0000750556 sti:VisaInterestMember 2017-12-31 0000750556 us-gaap:PerformingFinancingReceivableMember sti:LoansHeldForInvestmentMember 2017-12-31 0000750556 us-gaap:NonperformingFinancingReceivableMember sti:LoansHeldForInvestmentMember 2018-12-31 0000750556 us-gaap:PerformingFinancingReceivableMember sti:LoansHeldForInvestmentMember 2018-12-31 0000750556 us-gaap:NonperformingFinancingReceivableMember sti:LoansHeldForInvestmentMember 2017-12-31 0000750556 us-gaap:TotalReturnSwapMember 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:LoansHeldForInvestmentMember us-gaap:InterestIncomeMember 2018-01-01 2018-12-31 0000750556 srt:MaximumMember us-gaap:FinancialGuaranteeMember 2017-01-01 2017-12-31 0000750556 sti:NettedcounterpartybalancegainsMember 2018-12-31 0000750556 us-gaap:TotalReturnSwapMember 2017-12-31 0000750556 sti:NettedcounterpartybalanceMember 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:LoansHeldForInvestmentMember us-gaap:InterestIncomeMember 2016-01-01 2016-12-31 0000750556 sti:CreditSupportAnnexMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember sti:InterestratefuturesMember 2018-12-31 0000750556 us-gaap:CreditRiskContractMember 2018-12-31 0000750556 srt:MinimumMember us-gaap:FinancialGuaranteeMember 2017-01-01 2017-12-31 0000750556 sti:VisaInterestMember us-gaap:OtherContractMember 2017-12-31 0000750556 srt:MoodysBa1RatingMember sti:CreditSupportAnnexMember 2018-12-31 0000750556 us-gaap:FinancialGuaranteeMember 2017-12-31 0000750556 srt:MoodysBaa2RatingMember sti:CreditSupportAnnexMember 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2018-01-01 2018-12-31 0000750556 us-gaap:CreditRiskContractMember 2017-12-31 0000750556 sti:TradingAssetsMember 2017-12-31 0000750556 srt:MinimumMember us-gaap:FinancialGuaranteeMember 2018-01-01 2018-12-31 0000750556 srt:MaximumMember sti:AdditionalTerminationEventMember 2018-12-31 0000750556 sti:NettedcounterpartybalanceMember 2017-12-31 0000750556 sti:LoansHeldForSaleMember sti:InterestratefuturesMember 2017-12-31 0000750556 us-gaap:EquityContractMember sti:EquityFuturesMember 2018-12-31 0000750556 sti:TradingAssetsMember 2018-12-31 0000750556 srt:MaximumMember us-gaap:FinancialGuaranteeMember 2018-01-01 2018-12-31 0000750556 sti:DerivativeliabilitypositionscontainingprovisionsconditionedondowngradesMember 2017-12-31 0000750556 sti:VisaInterestMember us-gaap:OtherContractMember 2018-12-31 0000750556 sti:DerivativeliabilitypositionscontainingprovisionsconditionedondowngradesMember 2018-12-31 0000750556 srt:MoodysBaa3RatingMember sti:CreditSupportAnnexMember 2018-12-31 0000750556 us-gaap:EquityContractMember sti:EquityFuturesMember 2017-12-31 0000750556 us-gaap:FinancialGuaranteeMember 2018-01-01 2018-12-31 0000750556 sti:AdditionalTerminationEventMember 2018-12-31 0000750556 sti:MortgageServicingRightsMember sti:InterestratefuturesMember 2018-12-31 0000750556 sti:MortgageServicingRightsMember sti:InterestratefuturesMember 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:LoansHeldForInvestmentMember us-gaap:InterestIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:FinancialGuaranteeMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherTradingMember sti:InterestratefuturesMember 2017-12-31 0000750556 us-gaap:CreditDefaultSwapBuyingProtectionMember 2017-12-31 0000750556 us-gaap:TradingLiabilitiesMember 2017-12-31 0000750556 us-gaap:FinancialGuaranteeMember 2018-12-31 0000750556 us-gaap:OtherTradingMember sti:InterestratefuturesMember 2018-12-31 0000750556 srt:MaximumMember us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2018-01-01 2018-12-31 0000750556 srt:MinimumMember us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2017-01-01 2017-12-31 0000750556 srt:MinimumMember us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2018-01-01 2018-12-31 0000750556 us-gaap:TradingLiabilitiesMember 2018-12-31 0000750556 sti:NettedcounterpartybalancegainsMember 2017-12-31 0000750556 srt:MaximumMember us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:CreditRiskContractMember 2018-12-31 0000750556 us-gaap:EquityContractMember us-gaap:NondesignatedMember 2018-12-31 0000750556 us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:CreditRiskContractMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:ForeignExchangeContractMember us-gaap:NondesignatedMember 2018-12-31 0000750556 us-gaap:FixedIncomeInterestRateMember us-gaap:FairValueHedgingMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:CreditRiskContractMember 2017-12-31 0000750556 us-gaap:OtherContractMember us-gaap:NondesignatedMember 2017-12-31 0000750556 us-gaap:FairValueHedgingMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 us-gaap:EquityContractMember us-gaap:NondesignatedMember 2017-12-31 0000750556 us-gaap:FixedIncomeInterestRateMember us-gaap:FairValueHedgingMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:NondesignatedMember 2017-12-31 0000750556 us-gaap:ForeignExchangeContractMember us-gaap:NondesignatedMember 2017-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:CommodityMember us-gaap:NondesignatedMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:CashFlowHedgingMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 us-gaap:CashFlowHedgingMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:OtherContractMember us-gaap:NondesignatedMember 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember us-gaap:FairValueHedgingMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember us-gaap:FairValueHedgingMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 us-gaap:CommodityMember us-gaap:NondesignatedMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:FairValueHedgingMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:CashFlowHedgingMember us-gaap:InterestRateContractMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:CashFlowHedgingMember us-gaap:InterestRateContractMember 2018-12-31 0000750556 us-gaap:NondesignatedMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:CreditRiskContractMember 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember sti:BrokeredTimeDepositsMember 2017-01-01 2017-12-31 0000750556 sti:BrokeredTimeDepositsMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:LongTermDebtMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:BrokeredTimeDepositsMember 2016-01-01 2016-12-31 0000750556 sti:LoansHeldForInvestmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:LoansHeldForInvestmentMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:LoansHeldForInvestmentMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember us-gaap:LongTermDebtMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:LongTermDebtMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:BrokeredTimeDepositsMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:LongTermDebtMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember sti:LoansHeldForInvestmentMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:LongTermDebtMember 2017-01-01 2017-12-31 0000750556 us-gaap:LongTermDebtMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember sti:BrokeredTimeDepositsMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember sti:BrokeredTimeDepositsMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember sti:LoansHeldForInvestmentMember 2018-01-01 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember sti:LoansHeldForInvestmentMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember us-gaap:LongTermDebtMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:LongTermDebtMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:BrokeredTimeDepositsMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember sti:LoansHeldForInvestmentMember 2016-01-01 2016-12-31 0000750556 sti:BrokeredTimeDepositsMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:FairValueHedgingMember us-gaap:LongTermDebtMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:CashFlowHedgingMember us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember 2016-01-01 2016-12-31 0000750556 us-gaap:OtherContractMember us-gaap:InterestRateLockCommitmentsMember us-gaap:NondesignatedMember sti:MortgageRelatedandCommercialRealEstateRelatedIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:CreditRiskContractMember sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:ForeignExchangeContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:NondesignatedMember 2017-01-01 2017-12-31 0000750556 us-gaap:NondesignatedMember 2018-01-01 2018-12-31 0000750556 us-gaap:CreditRiskContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember sti:LoansHeldForSaleMember us-gaap:NondesignatedMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherContractMember us-gaap:InterestRateLockCommitmentsMember us-gaap:NondesignatedMember sti:MortgageRelatedandCommercialRealEstateRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember sti:MortgageServicingRightsMember us-gaap:NondesignatedMember sti:MortgageRelatedIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherContractMember us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember sti:LoansHeldForSaleMember us-gaap:NondesignatedMember sti:MortgageRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:OtherContractMember us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:EquityContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:CreditRiskContractMember sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherContractMember us-gaap:InterestRateLockCommitmentsMember us-gaap:NondesignatedMember sti:MortgageRelatedandCommercialRealEstateRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:EquityContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:NondesignatedMember 2016-01-01 2016-12-31 0000750556 us-gaap:ForeignExchangeContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:CreditRiskContractMember sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:ForeignExchangeContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember sti:MortgageServicingRightsMember us-gaap:NondesignatedMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:InterestRateContractMember sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember sti:LoansHeldForSaleMember us-gaap:NondesignatedMember sti:MortgageRelatedIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherContractMember us-gaap:CommodityContractMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember sti:LoansHeldForInvestmentMember us-gaap:NondesignatedMember us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:CreditRiskContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2016-01-01 2016-12-31 0000750556 us-gaap:CreditRiskContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:EquityContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:InterestRateContractMember sti:MortgageServicingRightsMember us-gaap:NondesignatedMember sti:MortgageRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:InterestRateContractMember us-gaap:OtherTradingMember us-gaap:NondesignatedMember us-gaap:OtherTradingMember 2017-01-01 2017-12-31 0000750556 us-gaap:ExchangeTradedMember 2017-12-31 0000750556 sti:DerivativesNotSubjectToMasterNettingArrangementOrSimilarArrangementMemberMember 2018-12-31 0000750556 sti:DerivativesNotSubjectToMasterNettingArrangementOrSimilarArrangementMemberMember 2017-12-31 0000750556 us-gaap:ExchangeTradedMember 2018-12-31 0000750556 sti:DerivativesSubjectToMasterNettingArrangementOrSimilarArrangementMember 2018-12-31 0000750556 sti:DerivativesSubjectToMasterNettingArrangementOrSimilarArrangementMember 2017-12-31 0000750556 us-gaap:FairValueHedgingMember sti:BrokeredTimeDepositsMember us-gaap:NondesignatedMember 2018-01-01 2018-12-31 0000750556 us-gaap:FairValueHedgingMember sti:BrokeredTimeDepositsMember us-gaap:DesignatedAsHedgingInstrumentMember 2018-01-01 2018-12-31 0000750556 us-gaap:FairValueHedgingMember us-gaap:LongTermDebtMember us-gaap:NondesignatedMember 2018-01-01 2018-12-31 0000750556 us-gaap:FairValueHedgingMember us-gaap:LongTermDebtMember us-gaap:DesignatedAsHedgingInstrumentMember 2018-01-01 2018-12-31 0000750556 us-gaap:FairValueHedgingMember us-gaap:LongTermDebtMember 2018-01-01 2018-12-31 0000750556 us-gaap:FairValueHedgingMember sti:BrokeredTimeDepositsMember 2018-01-01 2018-12-31 0000750556 sti:TradingLoansMember 2017-12-31 0000750556 us-gaap:LongTermDebtMember 2017-12-31 0000750556 sti:TradingLoansMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:PerformingFinancingReceivableMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:PerformingFinancingReceivableMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:NonperformingFinancingReceivableMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:NonperformingFinancingReceivableMember 2018-12-31 0000750556 us-gaap:LongTermDebtMember 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:PerformingFinancingReceivableMember 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:PerformingFinancingReceivableMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueConcentrationOfCreditRiskMasterNettingArrangementsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueConcentrationOfCreditRiskMasterNettingArrangementsMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2017-12-31 0000750556 us-gaap:FairValueConcentrationOfCreditRiskMasterNettingArrangementsMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2017-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:AssetBackedSecuritiesMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2017-12-31 0000750556 sti:TradingLoansMember us-gaap:TradingRevenueMember 2016-01-01 2016-12-31 0000750556 sti:LoansHeldForSaleMember 2016-01-01 2016-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:TradingRevenueMember 2016-01-01 2016-12-31 0000750556 sti:TradingLoansMember us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 sti:TradingLoansMember sti:MortgageRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 sti:BrokeredTimeDepositsMember us-gaap:TradingRevenueMember 2016-01-01 2016-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:TradingRevenueMember 2016-01-01 2016-12-31 0000750556 sti:BrokeredTimeDepositsMember sti:MortgageRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 sti:TradingLoansMember 2016-01-01 2016-12-31 0000750556 sti:BrokeredTimeDepositsMember us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 sti:MortgageServicingRightsMember 2016-01-01 2016-12-31 0000750556 us-gaap:LongTermDebtMember us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:LongTermDebtMember sti:MortgageRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 sti:MortgageServicingRightsMember sti:MortgageRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:LongTermDebtMember us-gaap:TradingRevenueMember 2016-01-01 2016-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:OtherIncomeMember 2016-01-01 2016-12-31 0000750556 sti:LoansHeldForSaleMember sti:MortgageRelatedIncomeMember 2016-01-01 2016-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MarketApproachValuationTechniqueMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:IncomeApproachValuationTechniqueMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2018-12-31 0000750556 us-gaap:FairValueConcentrationOfCreditRiskMasterNettingArrangementsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USTreasurySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:USStatesAndPoliticalSubdivisionsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:OtherDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:EquitySecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:ResidentialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:USGovernmentAgenciesDebtSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueConcentrationOfCreditRiskMasterNettingArrangementsMember us-gaap:DerivativeFinancialInstrumentsAssetsMember 2018-12-31 0000750556 us-gaap:FairValueConcentrationOfCreditRiskMasterNettingArrangementsMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CommercialPaperMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0000750556 us-gaap:FairValueMeasurementsRecurringMember us-gaap:DerivativeFinancialInstrumentsLiabilitiesMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember sti:TradingLoansMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-01-01 2017-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueMeasurementsNonrecurringMember 2017-01-01 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel1Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-01-01 2018-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel2Member us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueMeasurementsNonrecurringMember 2018-12-31 0000750556 sti:OtherRealEstateOwnedMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 us-gaap:OtherAssetsMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsNonrecurringMember 2017-12-31 0000750556 us-gaap:LongTermDebtMember us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:TradingRevenueMember 2017-01-01 2017-12-31 0000750556 sti:TradingLoansMember 2017-01-01 2017-12-31 0000750556 sti:TradingLoansMember us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:TradingRevenueMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForSaleMember sti:MortgageRelatedIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:LongTermDebtMember sti:MortgageRelatedIncomeMember 2017-01-01 2017-12-31 0000750556 sti:TradingLoansMember us-gaap:TradingRevenueMember 2017-01-01 2017-12-31 0000750556 sti:TradingLoansMember sti:MortgageRelatedIncomeMember 2017-01-01 2017-12-31 0000750556 us-gaap:LongTermDebtMember us-gaap:TradingRevenueMember 2017-01-01 2017-12-31 0000750556 sti:MortgageServicingRightsMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForSaleMember 2017-01-01 2017-12-31 0000750556 sti:MortgageServicingRightsMember sti:MortgageRelatedIncomeMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:OtherIncomeMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember 2016-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember 2017-01-01 2017-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-01-01 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember 2017-01-01 2017-12-31 0000750556 us-gaap:AvailableforsaleSecuritiesMember 2017-01-01 2017-12-31 0000750556 sti:DerivativecontractsnetMember 2017-01-01 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember 2017-12-31 0000750556 sti:ResidentialMortgageLoansHeldForSaleMember 2017-01-01 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:CorporateDebtSecuritiesMember 2017-01-01 2017-12-31 0000750556 us-gaap:AvailableforsaleSecuritiesMember 2017-12-31 0000750556 sti:ResidentialMortgageLoansHeldForSaleMember 2017-12-31 0000750556 sti:LoansHeldForInvestmentMember 2017-12-31 0000750556 us-gaap:CorporateDebtSecuritiesMember 2016-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember 2016-12-31 0000750556 sti:DerivativecontractsnetMember 2016-12-31 0000750556 us-gaap:CorporateDebtSecuritiesMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember 2016-12-31 0000750556 sti:DerivativecontractsnetMember 2017-12-31 0000750556 us-gaap:AvailableforsaleSecuritiesMember 2016-12-31 0000750556 us-gaap:USStatesAndPoliticalSubdivisionsMember 2017-12-31 0000750556 sti:ResidentialMortgageLoansHeldForSaleMember 2016-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember 2016-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 sti:MortgageServicingRightsMember 2018-01-01 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember us-gaap:TradingRevenueMember 2018-01-01 2018-12-31 0000750556 sti:TradingLoansMember us-gaap:TradingRevenueMember 2018-01-01 2018-12-31 0000750556 sti:MortgageServicingRightsMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 sti:TradingLoansMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForSaleMember 2018-01-01 2018-12-31 0000750556 us-gaap:LongTermDebtMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 us-gaap:LongTermDebtMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 sti:TradingLoansMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForSaleMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 sti:TradingLoansMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForSaleMember us-gaap:TradingRevenueMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 sti:BrokeredTimeDepositsMember sti:MortgageRelatedIncomeMember 2018-01-01 2018-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:TradingRevenueMember 2018-01-01 2018-12-31 0000750556 sti:MortgageServicingRightsMember us-gaap:OtherIncomeMember 2018-01-01 2018-12-31 0000750556 sti:LoansHeldForInvestmentMember us-gaap:TradingRevenueMember 2018-01-01 2018-12-31 0000750556 us-gaap:LongTermDebtMember us-gaap:TradingRevenueMember 2018-01-01 2018-12-31 0000750556 us-gaap:EstimateOfFairValueFairValueDisclosureMember sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2017-12-31 0000750556 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel1Member sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:CarryingReportedAmountFairValueDisclosureMember sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel2Member sti:BrokeredTimeDepositsMember 2017-12-31 0000750556 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel2Member sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0000750556 us-gaap:EstimateOfFairValueFairValueDisclosureMember sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel1Member sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:FairValueInputsLevel3Member sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:CarryingReportedAmountFairValueDisclosureMember sti:BrokeredTimeDepositsMember 2018-12-31 0000750556 us-gaap:OtherDebtSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:CostApproachValuationTechniqueMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:IncomeApproachValuationTechniqueMember 2017-12-31 0000750556 us-gaap:MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MarketApproachValuationTechniqueMember 2017-12-31 0000750556 us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MarketApproachValuationTechniqueMember 2017-12-31 0000750556 us-gaap:AssetBackedSecuritiesMember us-gaap:FairValueInputsLevel3Member us-gaap:FairValueMeasurementsRecurringMember us-gaap:MarketApproachValuationTechniqueMember 2017-12-31 0000750556 sti:DerivativecontractsnetMember 2018-01-01 2018-12-31 0000750556 us-gaap:FairValueMeasurementsNonrecurringMember sti:NonmarketableEquitySecuritiesMember 2018-01-01 2018-12-31 0000750556