Lease Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	3 years 7 months 6 days	5 years 4 months 24 days
Operating Lease, Weighted Average Discount Rate, Percent	7.20%	8.00%
Operating Leases, Rent Expense	$ 25.7	$ 25.3	$ 30.3
Property, Plant and Equipment [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	11.7	13.8
Lease Operating Expense [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	14.0	11.9
Gathering and other expense [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	5.7	7.7
General and administrative expense [Member]
Lessor, Lease, Description [Line Items]
Lease, Cost	$ 6.0	$ 5.7