Employee Benefit Plans (Deferred Compensation Plan) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation plan, employee base salary deferral, maximum percentage (up to)	80.00%
Deferred compensation plan, employee bonus deferral, maximum percentage (up to)	100.00%
Deferred compensation plan, maximum contractual term	15 years
Deferred compensation plan	$ 100.0	$ 99.9
Deferred compensation plan liability	$ 96.0	$ 97.9
Employer Matching, Option 1
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation plan, employer matching contribution based on participant's compensation over established 401K limits	2.00%
Employer Matching, Option 2
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation plan, employer matching contribution based on percent of amount deferred	50.00%