Revenue Revenue - Textuals (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Maximum Percentage Of Revenue For Which Individual Customer Accounts For	9.10%	9.80%	10.70%
Service and Repair Revenue, Percentage of Total	4.00%
Net Contract Liability, Change from Prior Year	$ 2.2
Net Contract Liability, Percentage Change from Prior Period	(5.60%)
Contract with Customer, Liability, Revenue Recognized	$ 51.1
Revenue, Remaining Performance Obligation, Amount	777.2
Capitalized Contract Cost, Net	6.5	$ 8.1
Capitalized Contract Cost, Amortization	1.6	$ 1.3
Minimum [Member]
Revenue, Remaining Performance Obligation, Amount	650.0
Maximum [Member]
Revenue, Remaining Performance Obligation, Amount	$ 670.0