Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) - USD ($) $ in Thousands	Jun. 30, 2018		Mar. 31, 2018	Dec. 31, 2017		Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 602,952			$ 639,073
Loans, net of unearned income	27,701,740	[1]		27,658,929	[1]	$ 19,989,319
Less: Allowance for loan losses	185,462		$ 187,194	189,555		$ 197,257	$ 201,968	$ 202,068
Total net loans	27,516,278			27,469,374
Other assets	1,934,001			1,723,189
Total assets	41,076,795			41,423,388
Liabilities:
Term borrowings	1,227,281			1,218,097
Other liabilities	526,430			549,234
Total liabilities	36,527,046			36,842,900
On-Balance Sheet Consumer Loan Securitization
Assets:
Cash and due from banks	0			0
Loans, net of unearned income	18,921			24,175
Less: Allowance for loan losses	0			0
Total net loans	18,921			24,175
Other assets	38			47
Total assets	18,959			24,222
Liabilities:
Term borrowings	6,004			11,226
Other liabilities	1			2
Total liabilities	6,005			11,228
Rabbi Trusts Used for Deferred Compensation Plans
Assets:
Other assets	82,802			80,479
Total assets	82,802			80,479
Liabilities:
Other liabilities	61,925			61,733
Total liabilities	$ 61,925			$ 61,733

[1] June 30, 2018 and December 31, 2017 include $21.4 million and $22.7 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.