Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012		Dec. 31, 2011	Mar. 31, 2011		Dec. 31, 2010
Variable Interest Entity [Line Items]
Cash and due from banks	$ 349,604		$ 384,667	$ 337,002
Loans, net of unearned income	15,971,330	[1],[2]	16,397,127	15,972,372	[1],[2]
Less: Allowance for loan losses	346,016	[1],[2]	384,351	589,128	[1],[2]	664,799
Total net loans	15,625,314		16,012,776	15,383,244
Other assets	2,143,012		2,151,656	2,083,115
Total assets	25,678,969		24,789,384	24,438,344
Noninterest-bearing deposits	4,969,597		4,613,014	4,480,413
Term borrowings	2,340,706		2,481,660	2,514,754
Other liabilities	817,527		838,483	771,606
Total liabilities	23,004,796		22,104,747	21,798,287
Subordinated Debentures Subject To Mandatory Redemption [Member]
Variable Interest Entity [Line Items]
Term borrowings				103,100
Subordinated Debentures Subject To Mandatory Redemption Amount [Member]
Variable Interest Entity [Line Items]
Term borrowings	309,300
Variable Interest Entity Consolidated Carrying Amount Assets [Member] | On-Balance Sheet Consumer Loan Securitizations [Member]
Variable Interest Entity [Line Items]
Cash and due from banks	1,671			4,890
Loans, net of unearned income	154,533			722,317
Less: Allowance for loan losses	10,388			39,839
Total net loans	144,145			682,478
Other assets	4,477			16,729
Total assets	150,293			704,097
Variable Interest Entity Consolidated Carrying Amount Assets [Member] | Rabbi Trusts Used For Deferred Compensation Plans [Member]
Variable Interest Entity [Line Items]
Other assets	61,632			62,069
Total assets	61,632			62,069
Variable Interest Entity Consolidated Carrying Amount Liabilities [Member] | On-Balance Sheet Consumer Loan Securitizations [Member]
Variable Interest Entity [Line Items]
Noninterest-bearing deposits				1,137
Term borrowings	150,328			718,091
Other liabilities	48			103
Total liabilities	150,376			719,331
Variable Interest Entity Consolidated Carrying Amount Liabilities [Member] | Rabbi Trusts Used For Deferred Compensation Plans [Member]
Variable Interest Entity [Line Items]
Other liabilities	52,712			55,486
Total liabilities	$ 52,712			$ 55,486

[1] Balances as of March 31, 2012 and 2011 include $20.1 million and $36.5 million of reserves, respectively, and $467.0 million and $672.4 million of balances in restricted consumer real estate loans and secured borrowings, respectively.

[2] Balances as of March 31, 2012 and 2011 include $5.4 million and $3.3 million of reserves, respectively, and $38.0 million and $49.9 million of balances in restricted permanent mortgage loans and secured borrowings, respectively.