Schedule II - Valuation Accounts and Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$ 1.6	$ 1.6	$ 1.6
Charged to Expense	0.0	0.0	0.0
Deductions	0.0	0.0	0.0
Other	0.0	0.0	0.0
Ending balance	1.6	1.6	1.6
Deferred tax asset valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	106.4	103.1	166.9
Charged to Expense	4.8	3.3	10.9
Deductions	0.0	0.0	0.0
Other	0.0	0.0	(74.7)
Ending balance	$ 111.2	$ 106.4	$ 103.1