Benefit Plans, Reconciliation of Changes in Fair Value Measurement of Plan Assets (Details) - Significant Unobservable Inputs (Level 3) [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of changes in fair value measurement of plan assets [Roll Forward]
Beginning balance	$ 24.7	$ 20.3
Purchases, sales, settlements	0.0	0.0
Actual return on plan assets still held at reporting date	(4.4)	3.9
Foreign exchange impact	(0.3)	0.5
Ending balance	20.0	24.7
Fair Value Transfers [Abstract]
Fair value, assets, Level 3 transfers in, amount	0.0	0.0
Fair value, assets, Level 3 transfers out, amount	$ 0.0	$ 0.0