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Loans (Balances Of Commercial Loan Portfolio Classes, Disaggregated By PD Grade) (Details) (USD $)
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Allowance for loan losses $ 232,448,000us-gaap_LoansAndLeasesReceivableAllowance $ 253,809,000us-gaap_LoansAndLeasesReceivableAllowance $ 276,963,000us-gaap_LoansAndLeasesReceivableAllowance $ 384,351,000us-gaap_LoansAndLeasesReceivableAllowance
Total loans collectively evaluated for impairment 15,846,431,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment 14,941,780,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment 16,253,687,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment  
Total loans individually evaluated for impairment 342,345,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment 400,468,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment 454,895,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment  
Allowance - collectively evaluated for impairment 165,635,000us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment 175,658,000us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment 201,803,000us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment  
Allowance - individually evaluated for impairment 63,628,000us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 77,334,000us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 75,160,000us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1  
Allowance - purchased credit impaired loans 3,185,000us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAllowanceForLoanLosses 817,000us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAllowanceForLoanLosses    
Purchase credit impaired loans - recorded investment 41,390,000fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment 46,826,000fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment    
General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Total loans collectively evaluated for impairment 7,477,612,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember		 6,709,598,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember		    
Total loans individually evaluated for impairment 22,853,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember		 43,367,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember		    
Total commercial loans 7,505,541,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember		 6,752,965,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember		 [1]    
Purchase credit impaired loans - recorded investment 5,076,000fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember		      
Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Total loans collectively evaluated for impairment 1,163,018,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember		 790,609,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember		    
Total loans individually evaluated for impairment 0us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember		 0us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember		    
Total commercial loans 1,163,018,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember		 790,609,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember		 [1]    
Purchase credit impaired loans - recorded investment 0fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember		      
TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Total loans collectively evaluated for impairment 325,882,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 [2] 336,043,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 [2]    
Total loans individually evaluated for impairment 12,845,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 [2] 36,864,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 [2]    
Total commercial loans 338,727,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 [2] 372,907,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 [1],[2]    
LOCOM valuation allowance 26,200,000fhn_LowerOfCostOrMarketValuationAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 29,400,000fhn_LowerOfCostOrMarketValuationAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		    
Highest internal grade 13fhn_HighestInternalGrade
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		 13fhn_HighestInternalGrade
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		    
Purchase credit impaired loans - recorded investment 0fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember		      
Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Total loans collectively evaluated for impairment 1,189,595,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember		 1,032,256,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember		    
Total loans individually evaluated for impairment 16,912,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember		 20,898,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember		    
Total commercial loans 1,240,421,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember		 1,053,154,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember		 [1]    
Purchase credit impaired loans - recorded investment 33,914,000fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember		      
Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Total loans collectively evaluated for impairment 33,063,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember		 34,383,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember		    
Total loans individually evaluated for impairment 2,518,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember		 6,914,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember		    
Total commercial loans 37,296,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember		 41,297,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember		 [1]    
Purchase credit impaired loans - recorded investment 1,715,000fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember		      
Commercial Portfolio Segment [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Percent of total commercial loans 100.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 100.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		    
Allowance for loan losses 85,585,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 96,245,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 [1]    
Total loans collectively evaluated for impairment 10,189,170,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 8,902,889,000us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		    
Total loans individually evaluated for impairment 55,128,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 108,043,000us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		    
Total commercial loans 10,285,003,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 9,010,932,000us-gaap_LoansAndLeasesReceivableCommercial
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 [1]    
Allowance - collectively evaluated for impairment 76,508,000us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 80,350,000us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		    
Allowance - individually evaluated for impairment 5,969,000us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 15,895,000us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		    
Allowance - purchased credit impaired loans 3,108,000us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAllowanceForLoanLosses
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		      
Percent of loan collectively evaluated for impairment 99.00%fhn_PercentLoanCollectivelyEvaluatedForImpiarment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 99.00%fhn_PercentLoanCollectivelyEvaluatedForImpiarment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		    
Percent of loan individually evaluated for impairment 1.00%fhn_PercentLoanIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		 1.00%fhn_PercentLoanIndividuallyEvaluatedForImpairment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		    
Purchase credit impaired loans - recorded investment 40,705,000fhn_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesRecordedInvestment
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		      
Percent of loan purchased-credit impaired 0.00%fhn_PercentLoanPurchasedCreditImpaired
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialPortfolioSegmentMember		      
Commercial Loan P D Grade One [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 450,661,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 239,141,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		    
Percent of total commercial loans 4.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 3.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		    
Allowance for loan losses 70,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 85,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		    
Commercial Loan P D Grade One [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 450,465,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 239,141,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		    
Commercial Loan P D Grade One [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		    
Commercial Loan P D Grade One [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 [2]    
Commercial Loan P D Grade One [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 136,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		    
Commercial Loan P D Grade One [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 60,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeOneMember		    
Commercial Loan P D Grade Two [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 436,525,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 219,536,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		    
Percent of total commercial loans 4.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 2.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		    
Allowance for loan losses 130,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 80,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		    
Commercial Loan P D Grade Two [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 434,945,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 216,173,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		    
Commercial Loan P D Grade Two [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		    
Commercial Loan P D Grade Two [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 [2]    
Commercial Loan P D Grade Two [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,344,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 3,363,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		    
Commercial Loan P D Grade Two [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 236,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwoMember		    
Commercial Loan P D Grade Three [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 774,636,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 225,046,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		    
Percent of total commercial loans 8.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 2.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		    
Allowance for loan losses 201,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 206,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		    
Commercial Loan P D Grade Three [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 566,364,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 224,224,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		    
Commercial Loan P D Grade Three [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 134,230,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		    
Commercial Loan P D Grade Three [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 [2]    
Commercial Loan P D Grade Three [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 73,812,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 739,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		    
Commercial Loan P D Grade Three [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 230,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		 83,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThreeMember		    
Commercial Loan P D Grade Four [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 836,944,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 334,641,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		    
Percent of total commercial loans 8.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 4.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		    
Allowance for loan losses 408,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 410,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		    
Commercial Loan P D Grade Four [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 589,341,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 321,423,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		    
Commercial Loan P D Grade Four [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 202,287,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		    
Commercial Loan P D Grade Four [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 [2]    
Commercial Loan P D Grade Four [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 45,084,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 13,005,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		    
Commercial Loan P D Grade Four [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 232,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		 213,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourMember		    
Commercial Loan P D Grade Five [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,288,533,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 863,803,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		    
Percent of total commercial loans 13.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 10.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		    
Allowance for loan losses 2,372,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 1,331,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		    
Commercial Loan P D Grade Five [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 821,012,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 821,158,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		    
Commercial Loan P D Grade Five [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 247,058,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		    
Commercial Loan P D Grade Five [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 [2]    
Commercial Loan P D Grade Five [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 216,628,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 42,420,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		    
Commercial Loan P D Grade Five [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 3,835,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		 225,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFiveMember		    
Commercial Loan P D Grade Six [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,657,447,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 1,212,356,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		    
Percent of total commercial loans 16.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 13.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		    
Allowance for loan losses 5,286,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 1,643,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		    
Commercial Loan P D Grade Six [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,162,551,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 876,982,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		    
Commercial Loan P D Grade Six [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 314,671,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 96,287,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		    
Commercial Loan P D Grade Six [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 [2]    
Commercial Loan P D Grade Six [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 175,007,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 229,098,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		    
Commercial Loan P D Grade Six [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 5,218,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		 9,989,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSixMember		    
Commercial Loan P D Grade Seven [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,714,273,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 1,530,885,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		    
Percent of total commercial loans 17.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 17.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		    
Allowance for loan losses 8,517,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 2,578,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		    
Commercial Loan P D Grade Seven [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,325,968,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 1,135,378,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		    
Commercial Loan P D Grade Seven [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 157,410,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 172,236,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		    
Commercial Loan P D Grade Seven [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 [2]    
Commercial Loan P D Grade Seven [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 224,226,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 216,744,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		    
Commercial Loan P D Grade Seven [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 6,669,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		 6,527,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeSevenMember		    
Commercial Loan P D Grade Eight [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 950,191,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 1,467,589,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		    
Percent of total commercial loans 9.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 16.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		    
Allowance for loan losses 9,307,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 4,426,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		    
Commercial Loan P D Grade Eight [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 699,334,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 953,398,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		    
Commercial Loan P D Grade Eight [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 42,730,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 295,436,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		    
Commercial Loan P D Grade Eight [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 [2]    
Commercial Loan P D Grade Eight [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 200,463,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 218,619,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		    
Commercial Loan P D Grade Eight [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 7,664,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		 136,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeEightMember		    
Commercial Loan P D Grade Nine [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 709,592,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 962,969,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		    
Percent of total commercial loans 7.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 11.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		    
Allowance for loan losses 8,901,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 8,381,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		    
Commercial Loan P D Grade Nine [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 531,979,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 683,223,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		    
Commercial Loan P D Grade Nine [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 58,997,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 167,533,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		    
Commercial Loan P D Grade Nine [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 [2]    
Commercial Loan P D Grade Nine [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 117,782,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 111,260,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		    
Commercial Loan P D Grade Nine [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 834,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		 953,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeNineMember		    
Commercial Loan P D Grade Ten [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 289,201,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 518,077,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		    
Percent of total commercial loans 3.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 6.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		    
Allowance for loan losses 4,806,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 7,276,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		    
Commercial Loan P D Grade Ten [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 244,574,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 402,532,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		    
Commercial Loan P D Grade Ten [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 5,635,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 48,802,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		    
Commercial Loan P D Grade Ten [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 [2]    
Commercial Loan P D Grade Ten [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 38,253,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 64,893,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		    
Commercial Loan P D Grade Ten [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 739,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		 1,850,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTenMember		    
Commercial Loan P D Grade Eleven [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 320,590,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 429,487,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		    
Percent of total commercial loans 3.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 5.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		    
Allowance for loan losses 6,887,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 9,687,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		    
Commercial Loan P D Grade Eleven [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 287,940,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 387,907,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		    
Commercial Loan P D Grade Eleven [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 10,169,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		    
Commercial Loan P D Grade Eleven [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 [2]    
Commercial Loan P D Grade Eleven [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 31,712,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 29,774,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		    
Commercial Loan P D Grade Eleven [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 938,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		 1,637,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeElevenMember		    
Commercial Loan P D Grade Twelve [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 147,922,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 166,870,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		    
Percent of total commercial loans 1.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 2.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		    
Allowance for loan losses 4,622,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 2,488,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		    
Commercial Loan P D Grade Twelve [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 117,431,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 129,741,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		    
Commercial Loan P D Grade Twelve [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		    
Commercial Loan P D Grade Twelve [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 [2] 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 [2]    
Commercial Loan P D Grade Twelve [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 29,453,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 32,796,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		    
Commercial Loan P D Grade Twelve [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,038,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		 4,333,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeTwelveMember		    
Commercial Loan P D Grade Thirteen [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 421,004,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 514,950,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		    
Percent of total commercial loans 4.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 6.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		    
Allowance for loan losses 3,590,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 9,047,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		    
Commercial Loan P D Grade Thirteen [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 87,840,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 163,458,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		    
Commercial Loan P D Grade Thirteen [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		    
Commercial Loan P D Grade Thirteen [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 325,882,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 [2] 331,940,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 [2]    
Commercial Loan P D Grade Thirteen [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 6,116,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 16,666,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		    
Commercial Loan P D Grade Thirteen [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 1,166,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		 2,886,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeThirteenMember		    
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 191,651,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 217,539,000us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		    
Percent of total commercial loans 2.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 2.00%fhn_LoanBalancesAsPercentageOfCommercialLoans
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		    
Allowance for loan losses 21,411,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 32,712,000us-gaap_LoansAndLeasesReceivableAllowance
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		    
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | General C I [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 157,868,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 154,860,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_GeneralCIMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		    
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | Loans To Mortgage Companies [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 146,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_LoansToMortgageCompaniesMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		    
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | TRUPs [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 [2] 4,103,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_TRUPsMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 [2]    
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | Income C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade 29,579,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 52,879,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_IncomeCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		    
Commercial Loan P D Grade Fourteen Fifteen Sixteen [Member] | Residential C R E [Member]        
Accounts, Notes, Loans and Financing Receivable [Line Items]        
Commercial loan, Disaggregated by PD grade $ 4,204,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		 $ 5,551,000us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= fhn_ResidentialCREMember
/ us-gaap_InternalCreditAssessmentAxis
= fhn_CommercialLoanPDGradeFourteenFifteenSixteenMember		    
[1]

December 31, 2013 table excludes PCI loans amounting to $45.9 million ($.8 million of allowance).
[2]

Balances as of December 31, 2014 and 2013, presented net of $26.2 million and $29.4 million, respectively, in lower of cost or market (“LOCOM”) valuation allowance. Based on the underlying structure of the notes, the highest possible internal grade is "13".