Pension, Savings, And Other Employee Benefits (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Estimated social security benefits age		65 years
Contributions to non-qualified plans		$ 165,000	$ 0
First Horizon National Corporation | Expected reduction to interest cost in 2016 [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost		$ (5,800)
Non Qualified Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Contributions to non-qualified plans					$ 4,900
Expected pension contribution				$ 5,200
Savings Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer investment in qualified defined contribution plan		100.00%	100.00%
Maximum percent of employee pre-tax contributions that may be matched by the Company		6.00%	6.00%
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
ASC 715 curtailment gain	$ 8,300
Tax Affected Adjustment To Accumulated Other Comprehensive Income	5,300		$ 5,300
Reduction in projected benefit obligation	$ 1,000