Leases - Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease costs	$ 14.2	$ 15.3
Variable lease costs	6.2	5.4
Sublease income	(2.1)	(0.4)
Total lease costs	18.3	20.3
Operating cash flows from operating leases (fixed payments)	14.9	15.7
Operating cash flows from operating leases (liability reduction)	$ 12.8	$ 12.8