Significant Commitments by Category (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Commitments and Contingencies Disclosure [Line Items]
Number of drilling rigs	2
Commitments
Commitment length	5 years
Estimated Litigation Liability, Current	$ 100
Gathering and Intermediate Transportation
Commitments
2020	12,962
2021	12,962
2022	12,962
2023	12,962
2024	12,962
Thereafter	24,827
Total	89,637
Other Commitments
Commitments
2020	317
2021	184
2022	0
2023	0
2024	0
Thereafter	0
Total	$ 501