Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) - USD ($)		Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Assets:
Cash and due from banks		$ 280,625,000	$ 300,811,000	$ 282,800,000
Loans, net of unearned income	[1]	17,574,994,000	17,686,502,000	16,732,123,000
Allowance for loan losses		204,034,000	210,242,000	228,328,000	$ 232,448,000
Total net loans		17,370,960,000	17,476,260,000	16,503,795,000
Other assets		1,392,160,000	1,436,291,000	1,416,635,000
Total assets		26,963,682,000	26,192,637,000	25,713,319,000
Liabilities:
Term borrowings		1,323,749,000	1,312,677,000	1,570,646,000
Other liabilities		617,449,000	635,306,000	795,878,000
Total liabilities		24,320,734,000	$ 23,553,051,000	23,214,062,000
On Balance Sheet Consumer Loan Securitizations [Member]
Assets:
Cash and due from banks		309,000		872,000
Loans, net of unearned income		47,833,000		71,565,000
Allowance for loan losses		0		341,000
Total net loans		47,833,000		71,224,000
Other assets		75,000		242,000
Total assets		48,217,000		72,338,000
Liabilities:
Term borrowings		34,914,000		60,914,000
Other liabilities		4,000		4,000
Total liabilities		34,918,000		60,918,000
Rabbi Trusts Used For Deferred Compensation Plans [Member]
Assets:
Other assets		70,314,000		68,356,000
Total assets		70,314,000		68,356,000
Liabilities:
Other liabilities		52,214,000		52,349,000
Total liabilities		$ 52,214,000		$ 52,349,000

[1] March 31, 2016 and 2015 and December 31, 2015 include $31.2 million , $28.0 million and $29.7 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate properties in process of foreclosure.