Leases - Schedule of Right-of-Use Asset and Liability, Adjusted for Initial Direct Costs and Incentives (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Operating leases:
Operating lease assets		$ 7,060	$ 7,779
Current portion of operating lease liabilities		$ 1,713	$ 1,594
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:OperatingLeaseLiabilityCurrent	us-gaap:OperatingLeaseLiabilityCurrent
Operating lease liabilities		$ 18,998	$ 17,239
Total operating lease liabilities		20,711	18,833
Finance leases:
Proved property	[1]	124,299	124,299
Other current liabilities		$ 20,645	$ 17,509
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Other long-term liabilities		$ 46,101	$ 62,026
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent
Total finance lease liabilities		$ 66,746	$ 79,535

[1] The HP-I is utilized in the Company’s oil and natural gas development activities and the right-of-use asset was capitalized and included in proved property and depleted as part of the full cost pool. Once items are included in the full cost pool, they are indistinguishable from other proved properties. The capitalized costs within the full cost pool are amortized over the life of the total proved reserves using the unit-of-production method, computed quarterly.