Variable Interest Entities (Summary Of VIE Not Consolidated By FHN) (Details) - Entity [Domain] - USD ($)	Jun. 30, 2015		Dec. 31, 2014	Jun. 30, 2014
Variable Interest Entity [Line Items]
Loans, net of unearned income	$ 16,936,772,000	[1]	$ 16,230,166,000	$ 15,795,709,000
Term borrowings	1,557,647,000		1,880,105,000	1,501,209,000
Trading securities	1,133,490,000		1,194,391,000	1,150,280,000
Total MSR recognized by FHN	2,158,000			3,197,000
Custodial balances	5,366,936,000		5,195,656,000	4,513,800,000
Securities available for sale	3,648,860,000	[2]	$ 3,556,613,000	3,576,542,000	[3]
Low Income Housing Partnerships [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	68,405,000	[4]		60,134,000	[5]
Maximum loss exposure, contractual funding commitments	12,000,000			6,500,000
Liability Recognized	11,976,000	[4]		6,471,000	[5]
Low Income Housing Partnerships [Member] | Other Assets Member
Variable Interest Entity [Line Items]
Maximum loss exposure, current investments	56,400,000			53,700,000
Other Tax Credit Investments [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	21,690,000	[6],[7]		22,359,000	[8],[9]
Liability Recognized	0	[6],[7]		0	[8],[9]
Other Tax Credit Investments [Member] | Current Investment Funded By Borrowings [Member]
Variable Interest Entity [Line Items]
Maximum loss exposure, current investments	18,000,000			18,000,000
Small Issuer Trust Preferred Holdings [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	344,321,000	[10]		364,942,000	[11]
Liability Recognized	0	[10]		0	[11]
On Balance Sheet Trust Preferred Securitization [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	50,506,000	[12]		52,682,000	[13]
Liability Recognized	63,686,000	[12]		61,491,000	[13]
Loans, net of unearned income	112,500,000			112,500,000
Term borrowings	63,700,000			61,500,000
Trading securities	1,700,000			1,700,000
Proprietary Trust Preferred Issuances [Member]
Variable Interest Entity [Line Items]
Liability Recognized	206,186,000	[14]		206,186,000	[15]
Proprietary Agency Residential Mortgage Securitizations [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	24,664,000	[16]		35,118,000	[17]
Liability Recognized	0	[16]		0	[17]
Trading securities	4,900,000			6,400,000
Total MSR recognized by FHN	600,000			1,100,000
Proprietary Agency Residential Mortgage Securitizations [Member] | Other Assets Member
Variable Interest Entity [Line Items]
Aggregate servicing advances	19,100,000			27,600,000
Holdings Of Agency Mortgage Backed Securities [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	3,929,684,000	[10],[18]		3,703,941,000	[11],[19]
Liability Recognized	0	[10],[18]		0	[19]
Trading securities	473,800,000			371,700,000
Securities available for sale	3,500,000,000			3,300,000,000
Short Positions In Agency Mortgage Backed Securities [Member]
Variable Interest Entity [Line Items]
Liability Recognized	1,486,000	[14]		1,092,000	[15]
Commercial Loan Troubled Debt Restructurings [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	36,047,000	[20],[21]		57,157,000	[22],[23]
Maximum loss exposure, contractual funding commitments	5,100,000			3,100,000
Liability Recognized	0	[20],[21]		0
Loans, net of unearned income	$ 30,900,000			$ 54,000,000

[1] June 30, 2015 includes $28.3 million of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.

[2] Includes $ 3.2 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[3] Includes $ 3.4 billion of securities pledged to secure public deposits, securities sold under agreements to repu rchase, and for other purposes .

[4] Maximum loss exposure represents $ 56 . 4 million of current investments and $ 12 . 0 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 2016 .

[5] Maximum loss exposure represents $ 53.7 million of current investments and $ 6.5 million of accrued contractual funding commitments. Accrued funding commitments represent unconditional contractual obligations for futu re funding events, and are also recognized in Other Liabilities. FHN currently expects to be required to fund these accrued commitments by the end of 2016 .

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

[7] Maximum loss exposure represe nts current investment balance. Of the initial investment, $ 1 8 . 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 credi t.

[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 ho lder 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 $ 63.7 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 $ 61 . 5 million classified as Term borrowings.

[14] No exposure to loss due to the nature of FHN’s involvement.

[15] No expos ure to loss due to the nature of FHN’s involveme nt.

[16] Includes $ . 6 million classified as MSR related to proprietary and agency residential mortgage securitizations and $ 4 . 9 million classified as Trading securities related to proprietary residential mortgage securitizations. Aggregate servi cing advances of $ 19 . 1 million are classified as Other assets.

[17] Includes $ 1.1 million classified as MSR related to proprietary and agency residential mortgage securitizations and $ 6 . 4 million classified as Trading securities related to proprietary and agency residenti al mortga ge securitizations . Aggregate servicing advances of $ 27 . 6 million are classified as Other assets.

[18] Includes $ 473.8 million classified as Trading securities and $ 3 . 5 billion cla ssified as Securities available-for- sale.

[19] Includes $ 371 . 7 million classified as Trading securities and $ 3 . 3 billion cla ssified as Securities available-for- sale.

[20] A liability is not recognized as the loans are the only variable interests held in the troubled commercial borrowers’ operat ions.

[21] Maximum loss exposure represents $ 30 . 9 million of current receivables and $ 5 . 1 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring.

[22] A liability is not recognized as the loans are the only variable interests held in the troubled commercial borrowers’ operations.

[23] Maximum loss exposure represen ts $ 54 . 0 million of current receivables and $ 3 . 1 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring.