Benefit Plans, Amounts Recognized in Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Amounts recognized in Balance Sheet [Abstract]
Current liability	$ (60.3)	$ (50.7)
Non-current liability	(179.0)	(148.9)
Pension Benefits [Member]
Amounts recognized in Balance Sheet [Abstract]
Current liability	(1.4)	(1.1)
Non-current liability	(174.7)	(143.3)
Recognized liability	(176.1)	(144.4)
Post-Retirement Benefits [Member]
Amounts recognized in Balance Sheet [Abstract]
Current liability	(0.3)	(0.4)
Non-current liability	(4.3)	(5.5)
Recognized liability	$ (4.6)	$ (5.9)