Securities Purchased Under Agreements To Resell And Collateral Pledged By Company (Details) - USD ($)	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Securities Purchased under Agreements to Resell [Abstract]
Gross amounts of recognized assets	$ 767,483,000		$ 831,541,000
Gross amounts offset in the Statement of Condition	0		0
Net amounts of assets presented in the Statement of Condition	767,483,000	$ 615,773,000	831,541,000
Offsetting securities sold under agreements to repurchase	(37,261,000)		(1,581,000)
Securities collateral (not recognized on FHN's Statement of Condition)	(723,992,000)		(823,157,000)
Net amount	$ 6,230,000		$ 6,803,000