Revenue from Contracts with Customers - Contract Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Revenue from Contracts with Customers
Contract liability, Beginning of period	$ 3.1	$ 3.2	$ 3.3	$ 2.9
Deferral	3.0	2.9	6.2	5.8
Revenue recognized	(3.2)	(2.8)	(6.6)	(5.4)
Contract liability, End of period	2.9	3.3	2.9	3.3
Current contract liabilities	2.6		2.6		$ 2.9
Non-current contract liabilities	0.3		0.3		0.4
Total contract liabilities	$ 2.9	$ 3.3	$ 2.9	$ 3.3	$ 3.3