Acquisitions and Divestitures (Narrative) (Details) (USD $)						5 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013		Dec. 31, 2012	Jun. 07, 2013 Mountain National Bank [Member] number	Jun. 07, 2013 Mountain National Bank [Member] Acquired From FDIC [Member]	Jun. 07, 2013 Mountain National Bank [Member] As Recorded by FHN [Member]	Dec. 31, 2014 Branch Acquisition [Member] number
Business Acquisition [Line Items]
Acquisition date							Jun. 07, 2013
Business Acquisition, Name of Acquired Entity						Mountain National Bank
Number Of Bank Branches						12
Assets acquired							$ 452,000,000
Loans acquired							249,000,000
Deposits assumed							362,000,000
Asset discount							33,000,000
Goodwill	141,943,000	141,943,000	140,479,000	[1]	134,242,000			7,700,000
Number of bank branches FTBNA agreed to purchase									13
Deposits FTBNA will assume related to pending branch acquisition									$ 660,000,000
Deposit Premium									3.32%

[1] June 30, 2013 balance has been re-presented due to purchase accounting adjustments made in third quarter 2013.