Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Additional Fair Value Elements [Abstract]
Transfers in or out of Level 3	$ 0.0	$ 0.0
Fair Value, Measurements, Recurring [Member]
Additional Fair Value Elements [Abstract]
Deferred compensation plan assets	14.2	13.7
Supplementary pension plan assets	15.0	12.8
Cross currency rate swap	0.4	10.2
Interest rate swaps	(7.6)	(5.9)
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Additional Fair Value Elements [Abstract]
Deferred compensation plan assets	0.0	0.0
Supplementary pension plan assets	0.0	0.0
Cross currency rate swap	0.0	0.0
Interest rate swaps	0.0	0.0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Additional Fair Value Elements [Abstract]
Deferred compensation plan assets	14.2	13.7
Supplementary pension plan assets	15.0	12.8
Cross currency rate swap	0.4	10.2
Interest rate swaps	(7.6)	(5.9)
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Additional Fair Value Elements [Abstract]
Deferred compensation plan assets	0.0	0.0
Supplementary pension plan assets	0.0	0.0
Cross currency rate swap	0.0	0.0
Interest rate swaps	$ 0.0	$ 0.0