Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Assets:
Cash and due from banks	$ 275,262	$ 469,879	$ 349,604
Loans, net of unearned income	15,889,670	16,708,582	15,971,330
Allowance for loan losses	265,218	276,963	346,016	384,351
Total net loans	15,624,452	16,431,619	15,625,314
Other assets	1,663,092	1,670,840	1,802,675
Total assets	25,166,427	25,520,140	25,678,969
Liabilities:
Noninterest-bearing deposits	4,454,045	4,602,472	4,969,597
Term borrowings	2,197,864	2,226,482	2,340,706
Other liabilities	685,153	743,933	583,339
Total liabilities	22,566,700	23,010,934	23,004,796
Variable Interest Entity Consolidated Carrying Amount Assets [Member] | On Balance Sheet Consumer Loan Securitizations [Member]
Assets:
Cash and due from banks	243		1,671
Loans, net of unearned income	114,505		154,533
Allowance for loan losses	3,712		10,388
Total net loans	110,793		144,145
Other assets	1,647		4,477
Total assets	112,683		150,293
Variable Interest Entity Consolidated Carrying Amount Assets [Member] | Rabbi Trusts Used For Deferred Compensation Plans [Member]
Assets:
Other assets	62,053		61,632
Total assets	62,053		61,632
Variable Interest Entity Consolidated Carrying Amount Liabilities [Member] | On Balance Sheet Consumer Loan Securitizations [Member]
Liabilities:
Term borrowings	104,875		150,328
Other liabilities	24		48
Total liabilities	104,899		150,376
Variable Interest Entity Consolidated Carrying Amount Liabilities [Member] | Rabbi Trusts Used For Deferred Compensation Plans [Member]
Liabilities:
Other liabilities	49,720		52,712
Total liabilities	$ 49,720		$ 52,712