Income Taxes - Components of Income Tax Benefit (Provision) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Tax Disclosure [Abstract]
Current income tax expense	$ (0.2)	$ (0.2)	$ (0.4)	$ (0.3)
Deferred income tax expense	(9.8)	(18.8)	(5.8)	(29.6)
Income tax expense	(10.0)	(19.0)	(6.2)	(29.9)
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Expected income tax expense based on federal statutory tax rate	(8.3)	(15.4)	(10.5)	(29.9)
State income tax expense, net of federal benefit	(1.1)	(2.0)	(1.5)	(3.8)
Unit-based compensation	0.4	0.1	7.7	6.6
Other	(1.0)	(1.7)	(1.9)	(2.8)
Income tax expense	$ (10.0)	$ (19.0)	$ (6.2)	$ (29.9)