Securities Purchased Under Agreements To Resell And Collateral Pledged By Company (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Securities Purchased under Agreements to Resell [Abstract]
Gross amounts of recognized assets	$ 602,126		$ 480,543
Gross amounts offset in the Statement of Condition	0		0
Net amounts of assets presented in the Statement of Condition	602,126	601,891	480,543
Offsetting securities sold under agreements to repurchase	(3,455)		(12,766)
Securities collateral (not recognized on FHN's Statement of Condition)	(589,180)		(460,158)
Net amount	$ 9,491		$ 7,619