Fair Value Of Assets And Liabilities (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	$ 223,483		$ 225,242
Total securities available-for-sale	3,067,003		3,032,201
Total MSR recognized by FHN	129,291	144,069	186,958	207,319
Total other assets	363,455		330,032
Total assets	5,141,358		4,970,813
Other short-term borrowings	12,439		23,645
Total other liabilities	235,490		212,289
Total liabilities	718,560		734,849
Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0		0
Total securities available-for-sale	13,784		7,819
Total MSR recognized by FHN	0		0
Total other assets	45,168		37,556
Total assets	58,952		45,375
Other short-term borrowings	0		0
Total other liabilities	7,430		16,509
Total liabilities	7,430		16,509
Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	8,923		9,372
Total securities available-for-sale	3,038,058		3,003,022
Total MSR recognized by FHN	0		0
Total other assets	318,287		292,476
Total assets	4,708,489		4,478,397
Other short-term borrowings	0		0
Total other liabilities	224,555		194,510
Total liabilities	695,186		693,425
Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	214,560		215,870
Total securities available-for-sale	15,161		21,360
Total MSR recognized by FHN	129,291		186,958
Total other assets	0		0
Total assets	373,917		447,041
Other short-term borrowings	12,439		23,645
Total other liabilities	3,505		1,270
Total liabilities	15,944		24,915
U.S. Treasuries [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	39,996		46,250
U.S. Treasuries [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
U.S. Treasuries [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	39,996		46,250
U.S. Treasuries [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Government Agency Issued Mortgage-Backed Securities ("MBS") [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	1,383,724		1,501,767
Government Agency Issued Mortgage-Backed Securities ("MBS") [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Government Agency Issued Mortgage-Backed Securities ("MBS") [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	1,383,724		1,501,767
Government Agency Issued Mortgage-Backed Securities ("MBS") [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	1,589,376		1,423,894
Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	1,589,376		1,423,894
Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Other U.S. Government Agencies [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	13,153		19,927
Other U.S. Government Agencies [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Other U.S. Government Agencies [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	8,492		13,246
Other U.S. Government Agencies [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	4,661		6,681
States And Municipalities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	17,970		19,365
States And Municipalities [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
States And Municipalities [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	16,470		17,865
States And Municipalities [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	1,500		1,500
Corporate And Other Debt [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	521		540
Corporate And Other Debt [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	521		540
Corporate And Other Debt [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Corporate And Other Debt [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Venture Capital Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	9,000		13,179
Venture Capital Investments [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Venture Capital Investments [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Venture Capital Investments [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	9,000		13,179
Equity, Mutual Funds, And Other [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	13,263		7,279
Equity, Mutual Funds, And Other [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	13,263		7,279
Equity, Mutual Funds, And Other [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Equity, Mutual Funds, And Other [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total securities available-for-sale	0		0
Deferred Compensation Assets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	22,645		25,356
Deferred Compensation Assets [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	22,645		25,356
Deferred Compensation Assets [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Deferred Compensation Assets [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Derivatives, Forwards And Futures [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	22,523		12,200
Total other liabilities	7,430		16,509
Derivatives, Forwards And Futures [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	22,523		12,200
Total other liabilities	7,430		16,509
Derivatives, Forwards And Futures [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Total other liabilities	0		0
Derivatives, Forwards And Futures [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Total other liabilities	0		0
Derivatives, Interest Rate Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	318,287		292,476
Total other liabilities	224,546		194,504
Derivatives, Interest Rate Contracts [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Total other liabilities	0		0
Derivatives, Interest Rate Contracts [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	318,287		292,476
Total other liabilities	224,546		194,504
Derivatives, Interest Rate Contracts [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0		0
Total other liabilities	0		0
Derivatives, Other [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other liabilities	3,514		1,276
Derivatives, Other [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other liabilities	0		0
Derivatives, Other [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other liabilities	9		6
Derivatives, Other [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other liabilities	3,505		1,270
Capital Markets [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,337,559		1,164,757
Total trading liabilities - capital markets	470,631		498,915
Capital Markets [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,337,554		1,164,752
Total trading liabilities - capital markets	470,631		498,915
Capital Markets [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5		5
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | U.S. Treasuries [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	115,210		218,302
Total trading liabilities - capital markets	260,547		331,864
Capital Markets [Member] | U.S. Treasuries [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | U.S. Treasuries [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	115,210		218,302
Total trading liabilities - capital markets	260,547		331,864
Capital Markets [Member] | U.S. Treasuries [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | Government Agency Issued Mortgage-Backed Securities ("MBS") [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	469,805		361,421
Total trading liabilities - capital markets	473		238
Capital Markets [Member] | Government Agency Issued Mortgage-Backed Securities ("MBS") [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | Government Agency Issued Mortgage-Backed Securities ("MBS") [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	469,805		361,421
Total trading liabilities - capital markets	473		238
Capital Markets [Member] | Government Agency Issued Mortgage-Backed Securities ("MBS") [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	125,404		133,841
Total trading liabilities - capital markets			122
Capital Markets [Member] | Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets			0
Capital Markets [Member] | Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	125,404		133,841
Total trading liabilities - capital markets			122
Capital Markets [Member] | Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets			0
Capital Markets [Member] | Other U.S. Government Agencies [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	275,756		192,643
Total trading liabilities - capital markets	27,152		6,026
Capital Markets [Member] | Other U.S. Government Agencies [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | Other U.S. Government Agencies [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	275,756		192,643
Total trading liabilities - capital markets	27,152		6,026
Capital Markets [Member] | Other U.S. Government Agencies [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | States And Municipalities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	46,596		19,093
Total trading liabilities - capital markets			0
Capital Markets [Member] | States And Municipalities [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets			0
Capital Markets [Member] | States And Municipalities [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	46,596		19,093
Total trading liabilities - capital markets			0
Capital Markets [Member] | States And Municipalities [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets			0
Capital Markets [Member] | Corporate And Other Debt [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	295,056		239,210
Total trading liabilities - capital markets	182,209		160,665
Capital Markets [Member] | Corporate And Other Debt [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | Corporate And Other Debt [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	295,051		239,205
Total trading liabilities - capital markets	182,209		160,665
Capital Markets [Member] | Corporate And Other Debt [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5		5
Total trading liabilities - capital markets	0		0
Capital Markets [Member] | Equity, Mutual Funds, And Other [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	9,732		247
Total trading liabilities - capital markets	250
Capital Markets [Member] | Equity, Mutual Funds, And Other [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0
Capital Markets [Member] | Equity, Mutual Funds, And Other [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	9,732		247
Total trading liabilities - capital markets	250
Capital Markets [Member] | Equity, Mutual Funds, And Other [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Total trading liabilities - capital markets	0
Mortgage Banking [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	20,567		31,623
Mortgage Banking [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,667		8,775
Mortgage Banking [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	14,900		22,848
Mortgage Banking [Member] | Certificated Principal Only [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,667		8,775
Mortgage Banking [Member] | Certificated Principal Only [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking [Member] | Certificated Principal Only [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,667		8,775
Mortgage Banking [Member] | Certificated Principal Only [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking [Member] | Interest Only Trading Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	14,900		22,848
Mortgage Banking [Member] | Interest Only Trading Securities [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking [Member] | Interest Only Trading Securities [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0		0
Mortgage Banking [Member] | Interest Only Trading Securities [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 14,900		$ 22,848