Investment Securities (Schedule Of FHN's Available For Sale Securities) (Details) (USD $)	Jun. 30, 2013		Dec. 31, 2012	Jun. 30, 2012
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	$ 3,213,047,000	[1]		$ 3,160,646,000	[1]
Securities available for sale, Gross Unrealized Gains	48,840,000	[1]		105,587,000	[1]
Securities available for sale, Gross Unrealized Losses	(32,816,000)	[1]		(1,367,000)	[1]
Securities available for sale, Fair Value	3,229,071,000	[1]	3,061,808,000	3,264,866,000	[1]
Pledged available for sale securities	3,000,000,000			3,000,000,000
Frb [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	66,200,000			66,000,000
Fhlb Cincinnati Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	128,000,000			125,500,000
U S Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	39,991,000			39,993,000
Securities available for sale, Gross Unrealized Gains	6,000			3,000
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	39,997,000			39,996,000
Mortgage Backed Securities Issued By U S Government Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	960,543,000			1,306,114,000
Securities available for sale, Gross Unrealized Gains	36,205,000			77,610,000
Securities available for sale, Gross Unrealized Losses	(4,294,000)			0
Securities available for sale, Fair Value	992,454,000			1,383,724,000
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	1,970,151,000			1,563,120,000
Securities available for sale, Gross Unrealized Gains	12,409,000			27,623,000
Securities available for sale, Gross Unrealized Losses	(28,522,000)			(1,367,000)
Securities available for sale, Fair Value	1,954,038,000			1,589,376,000
U S Government Corporations And Agencies Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	2,687,000			12,815,000
Securities available for sale, Gross Unrealized Gains	167,000			338,000
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	2,854,000			13,153,000
U S States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	16,434,000			17,970,000
Securities available for sale, Gross Unrealized Gains	11,000			0
Securities available for sale, Gross Unrealized Losses	0			0
Securities available for sale, Fair Value	16,445,000			17,970,000
Equity and other
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	223,241,000	[2]		220,634,000	[3]
Securities available for sale, Gross Unrealized Gains	42,000	[2]		13,000	[3]
Securities available for sale, Gross Unrealized Losses	0	[2]		0	[3]
Securities available for sale, Fair Value	$ 223,283,000	[2]		$ 220,647,000	[3]

[1] Includes $3.0 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[2] Includes restricted investments in FHLB-Cincinnati stock of $128.0 million and FRB stock of $66.2 million. The remainder is money market, venture capital, and cost method investments.

[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.