Employee Benefit Plans (Pensions Plans with Benefit Obligation in Excess of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pension plans with a benefit obligation in excess of plan assets:
Projected benefit obligation	$ 357.2	$ 394.4
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation	353.4	390.4
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets	$ 275.0	$ 305.9