Sales - Contract Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Contract assets	$ 9.0	$ 12.8
Deferred revenue - current	87.6	87.0
Deferred revenue - noncurrent	58.3	63.2
Total contract liabilities	145.9	150.2
Contract liabilities, revenue recognized	$ 63.3
Minimum
Disaggregation of Revenue [Line Items]
Contract assets, estimated useful lives	3 years
Maximum
Disaggregation of Revenue [Line Items]
Contract assets, estimated useful lives	5 years
Deferred Sales Commissions
Disaggregation of Revenue [Line Items]
Net revenue-related contract assets	$ 81.2	$ 95.2