Securities Purchased Under Agreements To Resell And Collateral Pledged By Company (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Securities Purchased under Agreements to Resell [Abstract]
Gross amounts of recognized assets	$ 561,802		$ 576,355
Gross amounts offset in the Statement of Condition	0		0
Net amounts of assets presented in the Statement of Condition	561,802	412,614	576,355
Offsetting securities sold under agreements to repurchase	(53,382)		(30,584)
Securities collateral (not recognized on FHN's Statement of Condition)	(500,659)		(537,810)
Net amount	$ 7,761		$ 7,961