Employee Benefit Plans (Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Components of net periodic benefit cost:
Interest cost	$ 8.2	$ 9.3	$ 10.1
Expected return on plan assets	(11.3)	(10.8)	(11.5)
Recognized net actuarial (gain)	(1.1)	(0.4)	0.0
Amortization of prior service cost	0.1	0.1	0.1
Net periodic benefit (income)	$ (4.1)	$ (1.8)	$ (1.3)
Weighted average assumptions used to determine net periodic benefit cost:
Discount rate	3.55%	4.07%	4.19%
Expected return on plan assets	5.35%	5.36%	5.56%