Variable Interest Entities (Summary Of VIE Not Consolidated By FHN) (Details) - USD ($)		Sep. 30, 2015		Dec. 31, 2014	Sep. 30, 2014
Variable Interest Entity [Line Items]
Loans, net of unearned income		$ 16,725,492,000	[1]	$ 16,230,166,000	$ 15,812,017,000
Term borrowings		1,341,186,000		1,880,105,000	1,491,138,000
Trading securities		1,229,180,000		1,194,391,000	1,338,022,000
Custodial balances		5,391,385,000		5,195,656,000	4,603,826,000
Securities available for sale		3,673,641,000	[2]	$ 3,556,613,000	3,534,671,000	[3]
Low Income Housing Partnerships [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		76,982,000	[4]		63,921,000	[5]
Maximum loss exposure, contractual funding commitments		22,200,000			5,900,000
Liability Recognized		22,224,000	[4]		5,937,000	[5]
Low Income Housing Partnerships [Member] | Other Assets Member
Variable Interest Entity [Line Items]
Maximum loss exposure, current investments		54,800,000			58,000,000
Other Tax Credit Investments [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	[6],[7]	21,359,000			22,077,000
Liability Recognized	[6],[7]	0			0
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		344,291,000	[8]		364,912,000	[9]
Liability Recognized		0	[8]		0	[9]
On Balance Sheet Trust Preferred Securitization [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		50,037,000	[10]		52,320,000	[11]
Liability Recognized		64,137,000	[10]		61,853,000	[11]
Loans, net of unearned income		112,500,000			112,500,000
Term borrowings		64,100,000			61,900,000
Trading securities		1,700,000			1,700,000
Proprietary Agency Residential Mortgage Securitizations [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		25,105,000	[12]		26,973,000	[13]
Liability Recognized		0	[12]		0	[13]
Trading securities		4,600,000			6,100,000
Total MSR recognized by FHN		600,000			900,000
Proprietary Agency Residential Mortgage Securitizations [Member] | Other Assets Member
Variable Interest Entity [Line Items]
Aggregate servicing advances		19,900,000			19,900,000
Holdings Of Agency Mortgage Backed Securities [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		4,030,604,000	[8],[14]		3,843,125,000	[9],[15]
Liability Recognized	[8]	0	[14]		0	[15]
Trading securities		549,200,000			502,600,000
Securities available for sale		3,500,000,000			3,300,000,000
Short Positions In Agency Mortgage Backed Securities Member [Member]
Variable Interest Entity [Line Items]
Liability Recognized	[16]	896,000
Commercial Loan Troubled Debt Restructurings [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		29,280,000	[17],[18]		55,539,000	[19],[20]
Maximum loss exposure, contractual funding commitments		100,000			3,100,000
Liability Recognized		0	[17],[18]		0	[19],[20]
Loans, net of unearned income		$ 29,200,000			$ 52,400,000

[1] September 30, 2015 includes $30.7 million of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.

[2] Includes $ 2.9 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

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

[4] Maximum loss exposure represents $ 54 . 8 million of current investments and $ 22 . 2 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 $ 58.0 million of current investments and $ 5.9 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] 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.

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

[10] Includes $ 112 . 5 million classified as Loans, net of unearned income, and $ 1 . 7 million classified as Trading securities which are offset by $ 64.1 million classified as Term borrowings.

[11] Includes $ 112.5 million classified as Loans, net of unearned income, and $ 1.7 million classified as Trading securities which are offset by $ 61 . 9 million classified as Term borrowings.

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

[13] Includes $ .9 million classified as MSR related to proprietary and agency residential mortgage securitizations and $ 6 . 1 million classified as Trading securities related to proprietary and agency residentia l mortga ge securitizations . Aggregate servicing advances of $ 19 . 9 million are classified as Other assets.

[14] Includes $ 549.2 million classified as Trading securities and $ 3 . 5 billion cla ssified as Securities available-for- sale.

[15] Includes $ 502 . 6 million classified as Trading securities and $ 3 . 3 billion cla ssified as Securities available-for- sale.

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

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

[18] Maximum loss exposure represents $ 29 . 2 million of current receivables and $ . 1 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring.

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

[20] Maximum loss exposure represent s $ 52 . 4 million of current receivables and $ 3 . 1 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring.