Commitments and Contingencies - Schedule of Future Minimum Transportation Fees Due (Detail) $ in Thousands	Dec. 31, 2017 USD ($)	[1]
Disclosure Commitments And Contingencies Schedule Of Future Minimum Transportation And Gathering Fees [Abstract]
2018	$ 805,161
2019	825,231
2020	767,090
2021	733,133
2022	691,968
Thereafter	4,689,133
Transportation, Gathering and Processing Contracts	$ 8,511,716

[1] The amounts in this table represent the gross amounts that we are committed to pay; however, we will record in our financial statements our proportionate share of costs based on our working interest which can vary based on volumes produced.