Investment Securities (Schedule Of FHN's Available For Sale Securities) (Details) (USD $)	Jun. 30, 2012		Dec. 31, 2011	Jun. 30, 2011
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	$ 3,160,646,000	[1]		$ 3,135,438,000	[2]
Securities available for sale, Gross Unrealized Gains	105,587,000	[1]		95,039,000	[2]
Securities available for sale, Gross Unrealized Losses	(1,367,000)	[1]		0	[2]
Securities available for sale, Fair Value	3,264,866,000	[1]	3,066,272,000	3,230,477,000	[2]
Pledged available for sale securities	3,000,000,000			2,900,000,000
FHN [Member]
Schedule of Available-for-sale Securities [Line Items]
Pledged available for sale securities	500,000,000			1,100,000,000
FRB [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	66,000,000			66,100,000
U.S. Treasuries [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	39,993,000			46,073,000
Securities available for sale, Gross Unrealized Gains	3,000			177,000
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	39,996,000			46,250,000
Government Agency Issued Mortgage-Backed Securities ("MBS") [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	1,306,114,000			1,445,021,000
Securities available for sale, Gross Unrealized Gains	77,610,000			56,746,000
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	1,383,724,000			1,501,767,000
FHLB-Cincinnati Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	125,500,000			125,500,000
Government Agency Issued Collateralized Mortgage Obligations ("CMO") [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	1,563,120,000			1,386,962,000
Securities available for sale, Gross Unrealized Gains	27,623,000			36,932,000
Securities available for sale, Gross Unrealized Losses	(1,367,000)			0
Securities available for sale, Fair Value	1,589,376,000			1,423,894,000
Other U.S. Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	12,815,000			18,791,000
Securities available for sale, Gross Unrealized Gains	338,000			1,136,000
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	13,153,000			19,927,000
States And Municipalities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	17,970,000			19,365,000
Securities available for sale, Gross Unrealized Gains	0			0
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	17,970,000			19,365,000
Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	220,124,000	[3]		218,715,000	[4]
Securities available for sale, Gross Unrealized Gains	2,000	[3]		19,000	[4]
Securities available for sale, Gross Unrealized Losses	0	[3]		0	[4]
Securities available for sale, Fair Value	220,126,000	[3]		218,734,000	[4]
Other Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	510,000			511,000
Securities available for sale, Gross Unrealized Gains	11,000			29,000
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	$ 521,000			$ 540,000

[1] Includes $3.0 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes. Of this amount, $.5 billion was pledged as collateral for securities sold under repurchase agreements.

[2] Includes $2.9 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes. Of this amount, $1.1 billion was pledged as collateral for securities sold under repurchase agreements.

[3] Includes restricted investments in FHLB-Cincinnati stock of $125.5 million and FRB stock of $66.0 million. The remainder is money market, venture capital, and cost method investments.

[4] Includes restricted investments in FHLB-Cincinnati stock of $125.5 million and FRB stock of $66.1 million. The remainder is money market, venture capital, and cost method investments.