Components of Other Comprehensive Income/(loss) (Schedule of Changes in AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016		Sep. 30, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ (152,334)	$ (188,248)	$ (214,192)		$ (188,246)
Net unrealized gains/(losses)	(9,098)	15,427	52,558		13,331
Amounts reclassifed from AOCI	604	(3,855)	806		(1,761)
Other comprehensive income/(loss)	(8,494)	11,572	53,364	[1]	11,570	[1]
Ending Balance	(160,828)	(176,676)	(160,828)		(176,676)
Securities AFS
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	58,591	16,485	3,394		18,581
Net unrealized gains/(losses)	(7,887)	15,427	48,330		13,331
Amounts reclassifed from AOCI	0	0	(1,020)		0
Other comprehensive income/(loss)	(7,887)	15,427	47,310		13,331
Ending Balance	50,704	31,912	50,704		31,912
Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	4,691	0	0		0
Net unrealized gains/(losses)	(1,211)	0	4,228		0
Amounts reclassifed from AOCI	(359)	0	(1,107)		0
Other comprehensive income/(loss)	(1,570)	0	3,121		0
Ending Balance	3,121	0	3,121		0
Pension and Postretirement Plans
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(215,616)	(204,733)	(217,586)		(206,827)
Net unrealized gains/(losses)	0	0	0		0
Amounts reclassifed from AOCI	963	(3,855)	2,933		(1,761)
Other comprehensive income/(loss)	963	(3,855)	2,933		(1,761)
Ending Balance	$ (214,653)	$ (208,588)	$ (214,653)		$ (208,588)

[1] Due to the nature of the preferred stock issued by FHN and its subsidiaries, all components of Other comprehensive income/(loss) have been attributed solely to FHN as the controlling interest holder.