Commitments and Contingencies - Other Commitments (Detail) $ in Thousands	Dec. 31, 2018 USD ($)
Other Commitments [Line Items]
2019	$ 107,641
2020	103,189
2021	98,230
2022	100,523
2023	98,598
Thereafter	762,472
Total	1,270,653
Drilling Rig Commitments [Member]
Other Commitments [Line Items]
2019	1,287	[1]
Total	1,287	[1]
Firm Transportation [Member]
Other Commitments [Line Items]
2019	80,083	[2]
2020	80,303	[2]
2021	80,083	[2]
2022	80,083	[2]
2023	80,083	[2]
Thereafter	700,549	[2]
Total	1,101,184	[2]
Gas Processing, Gathering, and Compression Services [Member]
Other Commitments [Line Items]
2019	26,271	[3]
2020	22,886	[3]
2021	18,147	[3]
2022	20,440	[3]
2023	18,515	[3]
Thereafter	61,923	[3]
Total	$ 168,182	[3]

[1] Drilling rig commitments -The Company had contracts for the service of two rigs, which have both expired and the Company has entered into well-to-well contracts.  The values in the table represent the gross amounts that the Company is committed to pay and does not deduct amounts that other parties are responsible for as a result of cost sharing arrangements with working interest partners. The Company will record in its consolidated financial statements the Company’s proportionate share of costs based on its working interest, as applicable.

[2] Firm transportation -The Company has entered into firm transportation agreements with various pipelines in order to facilitate the delivery of production to market. These contracts commit the Company to transport minimum daily natural gas volumes at a negotiated rate, or pay for any deficiencies at a specified reservation fee rate. The amounts in this table represent the minimum daily volumes at the reservation fee rate. The values in the table represent the gross amounts that the Company is committed to pay and does not deduct amounts that other parties are responsible for as a result of cost sharing arrangements with working interest partners. The Company will record in its consolidated financial statements the Company’s proportionate share of costs based on its working interest.

[3] Gas processing, gathering, and compression services -Contractual commitments for gas processing, gathering and compression service agreements represent minimum commitments under long-term gas processing agreements as well as various gas compression agreements. The values in the table represent the gross amounts that the Company is committed to pay and does not deduct amounts that other parties are responsible for as a result of cost sharing arrangements with working interest partners. The Company will record in its consolidated financial statements its proportionate share of costs based on the Company’s working interest.