Leases - Schedule of Lease Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease cost	$ 4.0	$ 4.3	$ 12.1	$ 14.1
Sublease income	(0.6)	(0.6)	(1.7)	(1.7)
Total lease cost	$ 3.4	$ 3.7	$ 10.4	$ 12.4