Revenue Revenue - Textuals (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Maximum Percentage Of Revenue For Which Individual Customer Accounts For	9.80%	10.70%	11.10%
Service and Repair Revenue, Percentage of Total	3.00%
Net Contract Liability, Change from Prior Year	$ (0.9)
Net Contract Liability, Percentage Change from Prior Period	2.30%
Contract with Customer, Liability, Revenue Recognized	$ 42.7
Revenue, Remaining Performance Obligation, Amount	$ 853.6
Revenue, Performance Obligation, Description of Timing	we expect to recognize approximately 90% in revenue during 2020 and the remainder in 2021
Capitalized Contract Cost, Net	$ 8.6	$ 6.9
Capitalized Contract Cost, Amortization	$ 1.3