Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax (benefit) provision	[1]	$ 17,253	$ 30,016	$ 44,307	$ 54,255
Accounting Standards Update 2016-09 | Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax (benefit) provision				(2,000)
Accounting Standards Update 2016-09 | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax (benefit) provision				$ 1,000

[1] Provision/(benefit) for income taxes for consolidated results and the Corporate segment for the three and six months ended June 30, 2017, relative to the prior year periods, was affected by a decline in the effective tax rate in 2017 primarily related to the reversal of the valuation allowance for the deferred tax asset related to its 2012 federal capital loss carryforward based on capital gain transactions initiated in second quarter 2017. See Note 15 – Income Taxes in the Notes to Consolidated Financial Statements on FHN’s Form 10-K for the year ended December 31, 2016, for additional information.