Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012		Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2011		Jun. 30, 2011	Dec. 31, 2010
Variable Interest Entity [Line Items]
Restricted Cash and due from banks	$ 355,978			$ 384,667	$ 339,895
Loans, net of unearned income	16,523,783	[1],[2]		16,397,127	16,241,402	[1],[2]
Allowance for loan losses	281,744	[1],[2]	321,051	384,351	449,645	[1],[2]	524,091	664,799
Restricted Total net loans	16,242,039			16,012,776	15,791,757
Other assets ( Restricted-$1.9 million on September 30, 2012; $13.6 million on September 30, 2011; and $13.4 million on December 31, 2011)	1,986,891			2,151,656	2,169,628
Restricted Total assets	25,739,830			24,789,384	25,571,469
Noninterest-bearing deposits	4,569,113			4,613,014	4,412,375
Term borrowings	2,263,238			2,481,660	2,509,804
Other liabilities ( Restricted-$- on September 30, 2012; $.1 million on September 30, 2011 and December 31, 2011)	974,288			838,483	915,945
Total liabilities	23,207,942			22,104,747	22,828,239
Variable Interest Entity Consolidated Carrying Amount Assets [Member] | On Balance Sheet Consumer Loan Securitizations [Member]
Variable Interest Entity [Line Items]
Restricted Cash and due from banks	624				4,719
Loans, net of unearned income	121,959				665,744
Allowance for loan losses	4,384				32,369
Restricted Total net loans	117,575				633,375
Other assets ( Restricted-$1.9 million on September 30, 2012; $13.6 million on September 30, 2011; and $13.4 million on December 31, 2011)	1,907				13,645
Restricted Total assets	120,106				651,739
Variable Interest Entity Consolidated Carrying Amount Assets [Member] | Rabbi Trusts Used For Deferred Compensation Plans [Member]
Variable Interest Entity [Line Items]
Other assets ( Restricted-$1.9 million on September 30, 2012; $13.6 million on September 30, 2011; and $13.4 million on December 31, 2011)	61,409				60,113
Restricted Total assets	61,409				60,113
Variable Interest Entity Consolidated Carrying Amount Liabilities [Member] | On Balance Sheet Consumer Loan Securitizations [Member]
Variable Interest Entity [Line Items]
Term borrowings	113,342				653,120
Other liabilities ( Restricted-$- on September 30, 2012; $.1 million on September 30, 2011 and December 31, 2011)	16				66
Total liabilities	113,358				653,186
Variable Interest Entity Consolidated Carrying Amount Liabilities [Member] | Rabbi Trusts Used For Deferred Compensation Plans [Member]
Variable Interest Entity [Line Items]
Other liabilities ( Restricted-$- on September 30, 2012; $.1 million on September 30, 2011 and December 31, 2011)	49,579				49,911
Total liabilities	$ 49,579				$ 49,911

[1] Balances as of September 30, 2012 and 2011 include $14.7 million and $26.9 million of reserves, respectively, and $417.0 million and $623.3 million of balances in restricted consumer real estate loans and secured borrowings, respectively.

[2] Balances as of September 30, 2012 and 2011 include $.6 million and $5.5 million of reserves, respectively, and $14.2 million and $42.4 million of balances in restricted permanent mortgage loans and secured borrowings, respectively.