Income Taxes - Components of Income Tax Benefit (Provision) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Current income tax expense	$ (0.2)	$ (0.1)
Deferred income tax expense	(3.0)	(1.3)
Income tax expense	(3.2)	(1.4)
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Expected income tax benefit (expense) based on federal statutory rate	(8.1)	2.4
State income tax benefit (expense), net of federal benefit	(1.1)	0.2
Unit-based compensation	(2.0)	(2.5)
Change in valuation allowance	7.1	(1.2)
Other	0.9	(0.3)
Income tax expense	$ (3.2)	$ (1.4)