Variable Interest Entities (Summary Of VIE Not Consolidated By FHN) (Details) - USD ($) $ in Thousands	Jun. 30, 2017		Dec. 31, 2016		Jun. 30, 2016
Variable Interest Entity [Line Items]
Loans, net of unearned income	$ 19,989,319	[1]	$ 19,589,520	[1]	$ 18,589,337
Term borrowings	1,033,329		1,040,656
Trading securities	1,315,891		897,071
Securities available-for-sale	3,949,592	[2]	3,943,499	[3]
Low Income Housing Partnerships
Variable Interest Entity [Line Items]
Maximum Loss Exposure	73,890	[4]	73,582	[5]
Maximum loss exposure, contractual funding commitments	19,500		17,400
Liability Recognized	19,479		17,398
Low Income Housing Partnerships | Other Assets
Variable Interest Entity [Line Items]
Maximum loss exposure, current investments	54,400		56,200
Other Tax Credit Investments
Variable Interest Entity [Line Items]
Maximum Loss Exposure	20,951	[6],[7]	21,898	[8],[9]
Liability Recognized	0	[6],[7]	0	[8],[9]
Other Tax Credit Investments | Other Assets
Variable Interest Entity [Line Items]
Maximum loss exposure, current investments	18,000		18,000
Small Issuer Trust Preferred Holdings
Variable Interest Entity [Line Items]
Maximum Loss Exposure	332,913	[10]	332,985	[11]
Liability Recognized	0	[10]	0	[11]
On Balance Sheet Trust Preferred Securitization
Variable Interest Entity [Line Items]
Maximum Loss Exposure	49,361		49,361
Liability Recognized	64,812	[12]	64,812	[13]
Loans, net of unearned income	112,500		112,500
Term borrowings	64,800		64,800
Trading securities	1,700		1,700
Proprietary & Agency Residential Mortgage Securitizations
Variable Interest Entity [Line Items]
Maximum Loss Exposure	2,459		2,568
Liability Recognized	0		0
Holdings Of Agency Mortgage Backed Securities
Variable Interest Entity [Line Items]
Maximum Loss Exposure	4,346,895	[10]	4,163,313	[11]
Liability Recognized	0	[10],[14]	0	[11],[15]
Trading securities	600,000		400,000
Securities available-for-sale	3,800,000		3,800,000
Commercial Loan Troubled Debt Restructurings
Variable Interest Entity [Line Items]
Maximum Loss Exposure	33,673	[16]	42,696	[17]
Maximum loss exposure, contractual funding commitments	5,200		5,200
Liability Recognized	0	[16]	0	[17]
Loans, net of unearned income	28,400		37,500
Sale Leaseback Transaction
Variable Interest Entity [Line Items]
Maximum Loss Exposure	14,827	[18]	11,827	[19]
Liability Recognized	$ 0		$ 0

[1] June 30, 2017 and December 31, 2016 include $28.8 million and $28.5 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate properties in process of foreclosure.

[2] Includes $3.5 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[3] Includes $3.3 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[4] Maximum loss exposure represents $54.4 million of current investments and $19.5 million of accrued contractual funding commitments. Accrued funding commitments represent unconditional contractual obligations for future funding events, and are also recognized in Other liabilities. FHN currently expects to be required to fund these accrued commitments by the end of 2020.

[5] Maximum loss exposure represents $56.2 million of current investments and $17.4 million of accrued contractual funding commitments. Accrued funding commitments represent unconditional contractual obligations for future funding events, and are also recognized in Other liabilities. FHN currently expects to be required to fund these accrued commitments by the end of 2017.

[6] A liability is not recognized as investments are written down over the life of the related tax credit.

[7] Maximum loss exposure represents current investment balance. Of the initial investment, $18.0 million was funded through loans from community development enterprises.

[8] A liability is not recognized as investments are written down over the life of the related tax credit.

[9] Maximum loss exposure represents current investment balance. Of the initial investment, $18.0 million was funded through loans from community development enterprises.

[10] Maximum loss exposure represents the value of current investments. A liability is not recognized as FHN is solely a holder of the trusts’ securities.

[11] Maximum loss exposure represents the value of current investments. A liability is not recognized as FHN is solely a holder of the trusts’ securities.

[12] Includes $112.5 million classified as Loans, net of unearned income, and $1.7 million classified as Trading securities which are offset by $64.8 million classified as Term borrowings.

[13] Includes $112.5 million classified as Loans, net of unearned income, and $1.7 million classified as Trading securities which are offset by $64.8 million classified as Term borrowings.

[14] Includes $.6 billion classified as Trading securities and $3.8 billion classified as Securities available-for-sale.

[15] Includes $.4 billion classified as Trading securities and $3.8 billion classified as Securities available-for-sale.

[16] Maximum loss exposure represents $28.4 million of current receivables and $5.2 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring.

[17] Maximum loss exposure represents $37.5 million of current receivables and $5.2 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring.

[18] Maximum loss exposure represents the current loan balance plus additional funding commitments less amounts received from the buyer-lessor.

[19] Maximum loss exposure represents the current loan balance plus additional funding commitments less amounts received from the buyer-lessor.