Income Taxes - Components of Income Tax Benefit (Provision) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Current income tax expense	$ (0.2)	$ (0.1)
Deferred income tax benefit (expense)	4.0	(10.8)
Income tax benefit (expense)	3.8	(10.9)
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Expected income tax expense based on federal statutory tax rate	(2.2)	(14.5)
State income tax expense, net of federal benefit	(0.4)	(1.8)
Unit-based compensation	7.3	6.5
Other	(0.9)	(1.1)
Income tax benefit (expense)	$ 3.8	$ (10.9)