Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) - USD ($) $ in Thousands	Mar. 31, 2018		Dec. 31, 2017		Mar. 31, 2017	Dec. 31, 2016
Assets:
Cash and due from banks	$ 459,820		$ 639,073
Loans, net of unearned income	27,249,793	[1]	27,658,929	[1]	$ 19,090,074
Less: Allowance for loan losses	187,194		189,555		$ 201,968	$ 202,068
Total net loans	27,062,599		27,469,374
Total assets	1,943,221		1,723,189
Total assets	40,463,195		41,423,388
Liabilities:
Term borrowings	1,214,967		1,218,097
Other liabilities	504,817		549,234
Total liabilities	35,890,667		36,842,900
On Balance Sheet Consumer Loan Securitizations
Assets:
Cash and due from banks	0		0
Loans, net of unearned income	21,302		24,175
Less: Allowance for loan losses	0		0
Total net loans	21,302		24,175
Total assets	42		47
Total assets	21,344		24,222
Liabilities:
Term borrowings	8,600		11,226
Other liabilities	2		2
Total liabilities	8,602		11,228
Rabbi Trusts Used For Deferred Compensation Plans
Assets:
Total assets	81,212		80,479
Total assets	81,212		80,479
Liabilities:
Other liabilities	61,258		61,733
Total liabilities	$ 61,258		$ 61,733

[1] March 31, 2018 and December 31, 2017 include $21.5 million and $22.7 million, respectively, of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.