Other Information (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Other current assets:
Natural gas and NGLs inventory	$ 44.9	$ 43.4
Prepaid expenses and other	13.8	14.4
Other current assets	58.7	57.8
Other current liabilities:
Accrued interest	35.7	37.1
Accrued wages and benefits, including taxes	22.5	31.5
Accrued ad valorem taxes	26.5	28.5
Capital expenditure accruals	10.6	42.4
Retainage liability	1.0	8.7
Short-term lease liability	16.3	21.1
Suspense producer payments	10.6	13.8
Operating expense accruals	8.4	10.8
Other	17.5	12.3
Other current liabilities	$ 149.1	$ 206.2