Significant Commitments by Category (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Minimum Rental Commitments
2017	$ 264
2018	190
2019	70
2020	41
2021	0
Thereafter	0
Total	565
Gathering and Intermediate Transportation [Member]
Commitments
Contractual Commitments Future Minimum Payments Due Current	9,646
2018	10,376
2019	11,702
2020	12,962
2021	12,962
Thereafter	76,674
Total	134,322
Drilling carry [Member]
Commitments
Contractual Commitments Future Minimum Payments Due Current	12,932
2018	8,691
2019	5,746
2020	0
2021	0
Thereafter	0
Total	27,369
Other Commitments
Commitments
Contractual Commitments Future Minimum Payments Due Current	596
2018	71
2019	0
2020	0
2021	0
Thereafter	0
Total	$ 667