Fair Value Of Assets And Liabilities (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $)	Mar. 31, 2015		Dec. 31, 2014	Mar. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 1,532,463,000		$ 1,194,391,000	$ 1,194,749,000
Loans held-for-sale	26,700,000			229,219,000
Securities available for sale	3,672,331,000	[1]	3,556,613,000	3,571,179,000	[2]
Total MSR recognized by FHN	2,342,000			4,687,000
Total other assets	176,935,000			194,487,000
Total assets	5,252,661,000			5,030,896,000
Total other liabilities	133,273,000			137,863,000
Total liabilities	946,414,000			805,120,000
Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	3,516,563,000			3,412,441,000
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0			0
Securities available for sale	25,870,000			26,482,000
Total MSR recognized by FHN	0			0
Total other assets	33,350,000			27,350,000
Total assets	59,220,000			53,832,000
Total other liabilities	7,828,000			2,738,000
Total liabilities	7,828,000			2,738,000
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	0			0
Securities available for sale	3,487,502,000			3,377,977,000
Total MSR recognized by FHN	0			0
Total other assets	141,243,000			162,450,000
Total assets	5,155,882,000			4,728,583,000
Total other liabilities	120,440,000			130,180,000
Total liabilities	933,581,000			797,437,000
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	26,700,000			229,219,000
Securities available for sale	3,191,000			7,982,000
Total MSR recognized by FHN	2,342,000			4,687,000
Total other assets	2,342,000			4,687,000
Total assets	37,559,000			248,481,000
Total other liabilities	5,005,000			4,945,000
Total liabilities	5,005,000			4,945,000
U.S. treasuries
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	100,000			39,990,000
U.S. treasuries | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
U.S. treasuries | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	100,000			39,990,000
U.S. treasuries | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Government Agency Issued Mortgage-Backed Securities ("MBS")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	762,850,000			792,562,000
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	762,850,000			792,562,000
Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Government Agency Issued Collateralized Mortgage Obligations ("CMO")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	2,716,147,000			2,531,770,000
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	2,716,147,000			2,531,770,000
Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Other U.S. Government Agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	1,691,000			2,182,000
Other U.S. Government Agencies | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Other U.S. Government Agencies | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Other U.S. Government Agencies | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	1,691,000			2,182,000
States And Municipalities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	9,905,000			15,155,000
States And Municipalities | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
States And Municipalities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	8,405,000			13,655,000
States And Municipalities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	1,500,000			1,500,000
Venture Capital Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale				4,300,000
Venture Capital Investments | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale				0
Venture Capital Investments | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale				0
Venture Capital Investments | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale				4,300,000
Equity, Mutual Funds, And Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	25,870,000			26,482,000
Equity, Mutual Funds, And Other | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	25,870,000			26,482,000
Equity, Mutual Funds, And Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Equity, Mutual Funds, And Other | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Securities available for sale	0			0
Deferred Compensation Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	26,440,000			23,335,000
Deferred Compensation Assets | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	26,440,000			23,335,000
Deferred Compensation Assets | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Deferred Compensation Assets | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Derivatives, Forwards And Futures
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	6,910,000			4,015,000
Total other liabilities	7,828,000			2,738,000
Derivatives, Forwards And Futures | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	6,910,000			4,015,000
Total other liabilities	7,828,000			2,738,000
Derivatives, Forwards And Futures | Level 2
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 | Level 3
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
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	140,976,000			162,450,000
Total other liabilities	120,440,000			130,180,000
Derivatives, Interest Rate Contracts | Level 1
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 | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	140,976,000			162,450,000
Total other liabilities	120,440,000			130,180,000
Derivatives, Interest Rate Contracts | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0			0
Total other liabilities	0			0
Derivatives, Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	267,000
Total other liabilities	5,005,000			4,945,000
Derivatives, Other | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0
Total other liabilities	0			0
Derivatives, Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	267,000
Total other liabilities	0			0
Derivatives, Other | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other assets	0
Total other liabilities	5,005,000			4,945,000
Capital Markets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,527,142,000			1,188,161,000
Total trading liabilities - capital markets	813,141,000			667,257,000
Capital Markets | Level 1
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 | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,527,137,000			1,188,156,000
Total trading liabilities - capital markets	813,141,000			667,257,000
Capital Markets | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,000			5,000
Total trading liabilities - capital markets	0			0
Capital Markets | U.S. treasuries
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	108,199,000			145,136,000
Total trading liabilities - capital markets	514,886,000			420,574,000
Capital Markets | U.S. treasuries | Level 1
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 | U.S. treasuries | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	108,199,000			145,136,000
Total trading liabilities - capital markets	514,886,000			420,574,000
Capital Markets | U.S. treasuries | Level 3
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 | Government Agency Issued Mortgage-Backed Securities ("MBS")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	547,569,000			412,994,000
Total trading liabilities - capital markets				1,083,000
Capital Markets | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - capital markets				0
Capital Markets | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	547,569,000			412,994,000
Total trading liabilities - capital markets				1,083,000
Capital Markets | Government Agency Issued Mortgage-Backed Securities ("MBS") | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - capital markets				0
Capital Markets | Government Agency Issued Collateralized Mortgage Obligations ("CMO")
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	312,086,000			124,304,000
Total trading liabilities - capital markets	1,000			503,000
Capital Markets | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 1
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 | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	312,086,000			124,304,000
Total trading liabilities - capital markets	1,000			503,000
Capital Markets | Government Agency Issued Collateralized Mortgage Obligations ("CMO") | Level 3
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 | Other U.S. Government Agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	161,317,000			86,672,000
Total trading liabilities - capital markets	17,863,000			9,739,000
Capital Markets | Other U.S. Government Agencies | Level 1
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 | Other U.S. Government Agencies | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	161,317,000			86,672,000
Total trading liabilities - capital markets	17,863,000			9,739,000
Capital Markets | Other U.S. Government Agencies | Level 3
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 | States And Municipalities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	57,181,000			29,787,000
Total trading liabilities - capital markets	1,643,000			1,436,000
Capital Markets | States And Municipalities | Level 1
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 | States And Municipalities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	57,181,000			29,787,000
Total trading liabilities - capital markets	1,643,000			1,436,000
Capital Markets | States And Municipalities | Level 3
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 | Corporate And Other Debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	339,565,000			382,346,000
Total trading liabilities - capital markets	276,748,000			233,287,000
Capital Markets | Corporate And Other Debt | Level 1
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 | Corporate And Other Debt | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	339,560,000			382,341,000
Total trading liabilities - capital markets	276,748,000			233,287,000
Capital Markets | Corporate And Other Debt | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,000			5,000
Total trading liabilities - capital markets	0			0
Capital Markets | Equity, Mutual Funds, And Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,225,000			6,922,000
Total trading liabilities - capital markets	2,000,000			635,000
Capital Markets | Equity, Mutual Funds, And Other | Level 1
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 | Equity, Mutual Funds, And Other | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,225,000			6,922,000
Total trading liabilities - capital markets	2,000,000			635,000
Capital Markets | Equity, Mutual Funds, And Other | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Total trading liabilities - capital markets	0			0
Mortgage Banking
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,321,000			6,588,000
Mortgage Banking | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	5,321,000	[3]		6,588,000
Mortgage Banking | Certificated Principal Only
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	4,013,000			4,764,000
Mortgage Banking | Certificated Principal Only | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Certificated Principal Only | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Certificated Principal Only | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	4,013,000			4,764,000
Mortgage Banking | Interest Only Trading Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	83,000			339,000
Mortgage Banking | Interest Only Trading Securities | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Interest Only Trading Securities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Interest Only Trading Securities | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	83,000			339,000
Mortgage Banking | Subordinated Bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	1,225,000			1,485,000
Mortgage Banking | Subordinated Bonds | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Subordinated Bonds | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	0			0
Mortgage Banking | Subordinated Bonds | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Trading securities	$ 1,225,000			$ 1,485,000

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

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

[3] The unobservable inputs for principal-only and interest-only trading securities and subordinated bonds are discussed in the Trading securities-mortgage paragraph.