Variable Interest Entities (Summary Of VIE Not Consolidated By FHN) (Details) - USD ($)		Mar. 31, 2016		Dec. 31, 2015	Mar. 31, 2015
Variable Interest Entity [Line Items]
Loans, net of unearned income	[1]	$ 17,574,994,000		$ 17,686,502,000	$ 16,732,123,000
Term borrowings		1,323,749,000		1,312,677,000	1,570,646,000
Trading securities		1,226,521,000		881,450,000	1,532,463,000
Securities available for sale, Fair Value		4,014,405,000	[2]	$ 3,929,846,000	3,672,331,000	[3]
Low Income Housing Partnerships [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		67,911,000	[4]		58,971,000	[5]
Maximum loss exposure, contractual funding commitments		14,700,000			3,600,000
Liability Recognized		14,676,000	[4]		3,609,000	[5]
Low Income Housing Partnerships [Member] | Other Assets [Member]
Variable Interest Entity [Line Items]
Maximum loss exposure, current investments		53,200,000			55,400,000
Other Tax Credit Investments [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		20,759,000	[6],[7]		21,360,000	[8],[9]
Liability Recognized		0	[6],[7]		0	[8],[9]
Other Tax Credit Investments [Member] | Other Assets [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		333,374,000	[10]		364,352,000	[11]
Liability Recognized		0	[10]		0	[11]
On Balance Sheet Trust Preferred Securitization [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		49,778,000	[12]		50,748,000	[13]
Liability Recognized		64,395,000	[12]		63,425,000	[13]
Loans, net of unearned income		112,500,000			112,500,000
Term borrowings		64,400,000			63,400,000
Trading securities		1,700,000			1,700,000
Proprietary Trust Preferred Issuances [Member]
Variable Interest Entity [Line Items]
Liability Recognized	[14]				206,186,000
Proprietary & Agency Residential Mortgage Securitizations [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		21,604,000	[15]		25,786,000	[16]
Liability Recognized		0	[15]		0	[16]
Trading securities		3,100,000			5,300,000
Total MSR recognized by FHN		500,000			700,000
Proprietary & Agency Residential Mortgage Securitizations [Member] | Other Assets [Member]
Variable Interest Entity [Line Items]
Aggregate servicing advances		18,000,000			19,800,000
Holdings Of Agency Mortgage Backed Securities [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		4,422,747,000	[10],[17]		4,338,653,000	[11],[18]
Liability Recognized		0	[10],[17]		0	[11],[18]
Trading securities		600,000,000			859,700,000
Securities available for sale, Fair Value		3,800,000,000			3,500,000,000
Short Positions In Agency Mortgage Backed Securities [Member]
Variable Interest Entity [Line Items]
Liability Recognized	[14]	17,000
Commercial Loan Troubled Debt Restructurings [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure		33,325,000	[19]		39,015,000	[20],[21]
Maximum loss exposure, contractual funding commitments		3,600,000			4,200,000
Liability Recognized		0	[19]		0	[20],[21]
Loans, net of unearned income		29,700,000			$ 34,800,000
Sale Leaseback Transaction [Member]
Variable Interest Entity [Line Items]
Maximum Loss Exposure	[22]	11,827,000
Liability Recognized	[22]	$ 0

[1] March 31, 2016 and 2015 and December 31, 2015 include $31.2 million , $28.0 million and $29.7 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate properties in process of foreclosure.

[2] Includes $ 3 .1 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 $ 53 . 2 million of current investments and $ 14 . 7 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 $ 55.4 million of current investments and $ 3.6 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 .

[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, $ 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 ho lder of the trusts’ securities.

[11] Maximum loss exposure represen ts 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 $ 64.4 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 $ 63 . 4 million classified as Term borrowings.

[14] No exposure to loss due to the nature of FHN’s involveme nt

[15] Includes $ . 5 million classified as MSR , $ 3 . 1 million classified as Trading securities , and $ 18 . 0 million of aggregate servicing advances .

[16] Includes $ .7 million classified as MSR related to proprietary and agency residential mortgage securitizations and $ 5 . 3 million classified as Trading securities related to proprietary and agency residential mortga ge securitizations . Aggregate servicing advances of $ 19 . 8 million are classified as Other assets.

[17] Includes $ .6 b illion classified as Trading securities and $ 3 . 8 billion cla ssified as Securities available-for- sale.

[18] Includes $ 859 . 7 million classified as Trading securities and $ 3 . 5 billion cla ssified as Securi ties available-for- sale.

[19] Ma ximum loss exposure represents $ 29.7 million of current receivables and $ 3.6 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring

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

[21] Maximum loss exposure represents $ 34 . 8 million of current receivables and $ 4 . 2 million of contractual funding commitments on loans related to commercial borrowers involved in a troubled debt restructuring.

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