Revenue - Timing of Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended					6 Months Ended			9 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020		Jun. 30, 2021	Jun. 30, 2020		Sep. 30, 2020	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 520.9	$ 479.9	$ 444.4	$ 418.7	[1]	$ 1,025.4	$ 814.4	[1]	$ 1,258.8	$ 1,738.7
Revenue recognized at a point in time
Disaggregation of Revenue [Line Items]
Revenue	212.5			173.8		417.5	352.6
Revenue recognized over time
Disaggregation of Revenue [Line Items]
Revenue	$ 308.4			$ 244.9		$ 607.9	$ 461.8

[1] See discussion in Note 1 - Basis of Presentation for further detail regarding the elimination of the International lag reporting.