Investment Securities (Schedule Of FHN's Investment Securities) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2015		Jun. 30, 2014		Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	$ 3,622,145,000	[1]	$ 3,551,256,000	[2]
Securities available for sale, Gross Unrealized Gains	49,925,000	[1]	60,999,000	[2]
Securities available for sale, Gross Unrealized Losses	(23,210,000)	[1]	(35,713,000)	[2]
Securities available for sale	3,648,860,000	[1]	3,576,542,000	[2]	$ 3,556,613,000
Pledged available for sale securities	3,200,000,000		3,400,000,000
Schedule Of Held To Maturity Securities [Line Items]
Securities held to maturity, Amortized cost	4,306,000		4,279,000		$ 4,292,000
Securities held to maturity, Gross Unrealized Gains	1,050,000		1,277,000
Securities held to maturity, Gross Unrealized Losses	0		0
Securities held to maturity, Fair Value	5,356,000		5,556,000
FRB [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	65,800,000		66,000,000
FHLB-Cincinnati Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Restricted investments	87,900,000		87,900,000
U.S. treasuries
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	100,000		39,995,000
Securities available for sale, Gross Unrealized Gains	0		4,000
Securities available for sale, Gross Unrealized Losses	0		0
Securities available for sale	100,000		39,999,000
Government Agency Issued Mortgage-Backed Securities ("MBS")
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	804,841,000		724,785,000
Securities available for sale, Gross Unrealized Gains	29,068,000		39,679,000
Securities available for sale, Gross Unrealized Losses	(3,269,000)		(1,622,000)
Securities available for sale	830,640,000		762,842,000
Government Agency Issued Collateralized Mortgage Obligations ("CMO")
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	2,624,151,000		2,582,242,000
Securities available for sale, Gross Unrealized Gains	20,836,000		21,211,000
Securities available for sale, Gross Unrealized Losses	(19,701,000)		(34,065,000)
Securities available for sale	2,625,286,000		2,569,388,000
Other U.S. Government Agencies
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	1,539,000		1,973,000
Securities available for sale, Gross Unrealized Gains	21,000		88,000
Securities available for sale, Gross Unrealized Losses	0		0
Securities available for sale	1,560,000		2,061,000
U S States And Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	9,455,000		15,155,000
Securities available for sale, Gross Unrealized Gains	0		0
Securities available for sale, Gross Unrealized Losses	0		0
Securities available for sale	9,455,000		15,155,000
Equity and other
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, Amortized Cost	182,059,000	[3]	187,106,000	[4]
Securities available for sale, Gross Unrealized Gains	0	[3]	17,000	[4]
Securities available for sale, Gross Unrealized Losses	(240,000)	[3]	(26,000)	[4]
Securities available for sale	181,819,000	[3]	187,097,000	[4]
Schedule Of Held To Maturity Securities [Line Items]
Securities held to maturity, Amortized cost	0
Securities held to maturity, Fair Value	0
U S States And Political Subdivisions [Member]
Schedule Of Held To Maturity Securities [Line Items]
Securities held to maturity, Amortized cost	4,306,000		4,279,000
Securities held to maturity, Gross Unrealized Gains	1,050,000		1,277,000
Securities held to maturity, Gross Unrealized Losses	0		0
Securities held to maturity, Fair Value	$ 5,356,000		$ 5,556,000

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

[2] Includes $ 3.4 billion of securities pledged to secure public deposits, securities sold under agreements to repu rchase, and for other purposes .

[3] Includes restricted investments in FHLB-Cincinnati stock of $ 87.9 million and FRB stock of $ 65.8 million. The remainder is money market and cost method investments.

[4] Includes restricted investments in FHLB-Cincinnati stock of $ 87.9 million and FRB stock of $ 66.0 million. The remainder is money market, venture capital, and cost method investments.