Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Lease liability	$ 87.6
Right-of-use assets	59.8	$ 80.4
Impairments	6.8	0.0
Office Lease
Lessee, Lease, Description [Line Items]
Lease liability	57.6	60.0
Right-of-use assets	32.4	39.8
Compression and Other Field Equipment
Lessee, Lease, Description [Line Items]
Lease liability	14.6	27.1
Right-of-use assets	14.6	27.1
Land
Lessee, Lease, Description [Line Items]
Lease liability	15.1	15.3
Right-of-use assets	12.5	12.9
Office Equipment
Lessee, Lease, Description [Line Items]
Lease liability	0.3	0.6
Right-of-use assets	$ 0.3	$ 0.6
Minimum | Compression and Other Field Equipment
Lessee, Lease, Description [Line Items]
Term of contract	1 year
Maximum | Compression and Other Field Equipment
Lessee, Lease, Description [Line Items]
Term of contract	3 years