Investment Securities (Schedule Of FHN's Available For Sale Securities) (Details) (USD $)	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	$ 3,168,118,000	[1]	$ 3,019,009,000	[2]
Securities available for sale, Gross Unrealized Gains	58,514,000	[1]	105,516,000	[2]
Securities available for sale, Gross Unrealized Losses	(39,689,000)	[1]	(896,000)	[2]
Securities available for sale	3,186,943,000	[1]	3,123,629,000	[2]	3,061,808,000
Pledged available for sale securities	2,900,000,000		2,800,000,000
Frb [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	66,000,000		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	39,993,000		54,995,000
Securities available for sale, Gross Unrealized Gains	3,000		1,000
Securities available for sale, Gross Unrealized Losses	0		0
Securities available for sale	39,996,000		54,996,000
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	838,077,000		1,191,811,000
Securities available for sale, Gross Unrealized Gains	40,944,000		79,639,000
Securities available for sale, Gross Unrealized Losses	(3,570,000)		0
Securities available for sale	875,451,000		1,271,450,000
Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	2,043,803,000		1,530,075,000
Securities available for sale, Gross Unrealized Gains	17,420,000		25,562,000
Securities available for sale, Gross Unrealized Losses	(36,102,000)		(896,000)
Securities available for sale	2,025,121,000		1,554,741,000
U S Government Corporations And Agencies Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	2,381,000		3,911,000
Securities available for sale, Gross Unrealized Gains	147,000		291,000
Securities available for sale, Gross Unrealized Losses	0		0
Securities available for sale	2,528,000		4,202,000
U S States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	15,155,000		17,970,000
Securities available for sale, Gross Unrealized Gains	0		0
Securities available for sale, Gross Unrealized Losses	0		0
Securities available for sale	15,155,000		17,970,000
Equity and other
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	228,709,000	[3]	220,247,000	[4]
Securities available for sale, Gross Unrealized Gains	0	[3]	23,000	[4]
Securities available for sale, Gross Unrealized Losses	(17,000)	[3]	0	[4]
Securities available for sale	$ 228,692,000	[3]	$ 220,270,000	[4]

[1] Includes $2.9 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[2] Includes $2.8 billion of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes.

[3] Includes restricted investments in FHLB-Cincinnati stock of $128.0 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 $66.0 million. The remainder is money market, venture capital, and cost method investments.