Other Long-term Liabilities - Components of Deferred Revenue (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$ 171.8	$ 168.5	$ 172.0
Splitter Agreement [Member]
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	129.0	129.0
Gas Contract Amendment [Member]
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	34.8	37.3
Other
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$ 8.0	$ 2.2