Premises, Equipment And Leases (Narrative) (Details)	12 Months Ended
Dec. 31, 2015
Property Plant And Equipment [Abstract]
Maximum duration of noncancelable operating leases, time period	30 years

Maximum Duration Of Noncancelable Operating Leases For Premises And Equipment.

No definition available.

Name:	fhn_MaximumDurationOfNoncancelableOperatingLeasesForPremisesAndEquipment
Namespace Prefix:	fhn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration