Income Taxes - Provision (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Current:
Federal									$ 1.7	$ (1.9)		$ 3.5
Foreign									2.6	4.6		7.4
State									0.0	0.0		0.1
Total current									4.3	2.7		11.0
Deferred:
Federal									1.3	(0.9)		1.2
Foreign									17.7	(7.4)		(4.8)
State									0.0	(0.1)		0.2
Total deferred									19.0	(8.4)		(3.4)
Total	$ 9.5	$ 15.4	$ (2.5)	$ 0.9	$ (0.3)	$ (3.1)	$ (2.0)	$ (0.3)	$ 23.3	$ (5.7)	[1]	$ 7.6

[1] As adjusted for the adoption of ASU 2020-06 using the full retrospective method.