Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011
Assets:
Cash and due from banks	$ 395,631		$ 469,879	$ 355,978
Loans, net of unearned income	15,408,556		16,708,582	16,523,783
Allowance for loan losses	255,710	261,934	276,963	281,744	321,051	384,351
Total net loans	15,152,846		16,431,619	16,242,039
Other assets	1,637,138		1,670,840	1,652,866
Total assets (Restricted - $.1 billion on September 30, 2013; September 30, 2012; and December 31, 2012)	24,193,341		25,520,140	25,739,830
Liabilities:
Term borrowings	1,771,288		2,226,482	2,263,238
Other liabilities	770,772		743,933	749,204
Total liabilities (Restricted - $.1 billion on September 30, 2013; September 30, 2012; and December 31, 2012)	21,760,048		23,010,934	23,207,942
On Balance Sheet Consumer Loan Securitizations [Member]
Assets:
Cash and due from banks	1,494			624
Loans, net of unearned income	104,052			121,959
Allowance for loan losses	3,217			4,384
Total net loans	100,835			117,575
Other assets	1,435			1,907
Total assets (Restricted - $.1 billion on September 30, 2013; September 30, 2012; and December 31, 2012)	103,764			120,106
Liabilities:
Term borrowings	93,700			113,342
Other liabilities	19			16
Total liabilities (Restricted - $.1 billion on September 30, 2013; September 30, 2012; and December 31, 2012)	93,719			113,358
Rabbi Trusts Used For Deferred Compensation Plans [Member]
Assets:
Other assets	63,238			61,409
Total assets (Restricted - $.1 billion on September 30, 2013; September 30, 2012; and December 31, 2012)	63,238			61,409
Liabilities:
Other liabilities	49,469			49,579
Total liabilities (Restricted - $.1 billion on September 30, 2013; September 30, 2012; and December 31, 2012)	$ 49,469			$ 49,579