Variable Interest Entities (Summary Of VIE Consolidated By FHN) (Details) - USD ($)	Sep. 30, 2015		Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Assets:
Cash and due from banks	$ 256,342,000			$ 349,171,000	$ 292,687,000
Loans, net of unearned income	16,725,492,000	[1]		16,230,166,000	15,812,017,000
Allowance for loan losses	210,814,000		$ 221,351,000	232,448,000	238,641,000	$ 243,628,000	$ 253,809,000
Total net loans	16,514,678,000			15,997,718,000	15,573,376,000
Other assets	1,418,317,000			1,385,572,000	1,355,046,000
Total assets	25,387,319,000			25,668,187,000	23,982,597,000
Liabilities:
Term borrowings	1,341,186,000			1,880,105,000	1,491,138,000
Other liabilities	622,586,000			649,359,000	551,615,000
Total liabilities	22,807,074,000			$ 23,086,597,000	21,370,783,000
On Balance Sheet Consumer Loan Securitizations [Member]
Assets:
Cash and due from banks	2,000,000				300,000
Loans, net of unearned income	59,258,000				81,111,000
Allowance for loan losses	54,000				812,000
Total net loans	59,204,000				80,299,000
Other assets	114,000				438,000
Total assets	61,318,000				81,037,000
Liabilities:
Term borrowings	48,491,000				70,720,000
Other liabilities	3,000				4,000
Total liabilities	48,494,000				70,724,000
Rabbi Trusts Used For Deferred Compensation Plans [Member]
Assets:
Other assets	66,490,000				66,290,000
Total assets	66,490,000				66,290,000
Liabilities:
Other liabilities	49,275,000				50,477,000
Total liabilities	$ 49,275,000				$ 50,477,000

[1] September 30, 2015 includes $30.7 million of held-to-maturity consumer mortgage loans secured by residential real estate in process of foreclosure.