Derivative Activities - Derivative Volumes Hedged and Average Hedge Prices (Detail)	Mar. 31, 2019 MMBTU / d bbl / d $ / MMBTU $ / bbl $ / gal
2019 Commodity Contract | Swaps | Natural Gas
Derivative [Line Items]
Volume Hedged | MMBTU / d	1,246,873
Weighted Average Hedge Price | $ / MMBTU	2.80
2019 Commodity Contract | Swaps | Crude Oil
Derivative [Line Items]
Volume Hedged | bbl / d	7,472
Weighted Average Hedge Price | $ / bbl	55.47
2019 Commodity Contract | Swaps | NGLs (C5-Natural Gasoline)
Derivative [Line Items]
Volume Hedged | bbl / d	2,658
Weighted Average Hedge Price | $ / gal	1.39
2019 Commodity Contract | Swaptions | Natural Gas
Derivative [Line Items]
Volume Hedged | MMBTU / d	150,000
Weighted Average Hedge Price | $ / MMBTU	2.81	[1]
2019 Commodity Contract | Collars | Crude Oil
Derivative [Line Items]
Volume Hedged | bbl / d	1,000
2019 Commodity Contract | Collars | Crude Oil | Minimum
Derivative [Line Items]
Weighted Average Hedge Price | $ / gal	63.00
2019 Commodity Contract | Collars | Crude Oil | Maximum
Derivative [Line Items]
Weighted Average Hedge Price | $ / gal	73.02
2020 Commodity Contract | Swaps | Natural Gas
Derivative [Line Items]
Volume Hedged | MMBTU / d	190,000
Weighted Average Hedge Price | $ / MMBTU	2.75
2020 Commodity Contract | Swaps | Crude Oil
Derivative [Line Items]
Volume Hedged | bbl / d	2,557
Weighted Average Hedge Price | $ / bbl	60.53
2020 Commodity Contract | Swaptions | Natural Gas
Derivative [Line Items]
Volume Hedged | MMBTU / d	140,000
Weighted Average Hedge Price | $ / MMBTU	2.78	[1]
November-December 2019 Commodity Contract | Swaptions | Natural Gas
Derivative [Line Items]
Volume Hedged | MMBTU / d	20,000
Weighted Average Hedge Price | $ / MMBTU	3.20	[1]
January-March 2020 Commodity Contract | Swaptions | Natural Gas
Derivative [Line Items]
Volume Hedged | MMBTU / d	20,000
Weighted Average Hedge Price | $ / MMBTU	3.20	[1]
April-June 2019 Commodity Contract | Swaps | NGLs (C2-Ethane)
Derivative [Line Items]
Volume Hedged | bbl / d	500
Weighted Average Hedge Price | $ / gal	0.35
April-June 2019 Commodity Contract | Swaps | NGLs (C3-Propane)
Derivative [Line Items]
Volume Hedged | bbl / d	8,500
Weighted Average Hedge Price | $ / gal	0.88
April-June 2019 Commodity Contract | Collars | NGLs (C3-Propane)
Derivative [Line Items]
Volume Hedged | bbl / d	1,000
April-June 2019 Commodity Contract | Collars | NGLs (C3-Propane) | Minimum
Derivative [Line Items]
Weighted Average Hedge Price | $ / gal	0.90
April-June 2019 Commodity Contract | Collars | NGLs (C3-Propane) | Maximum
Derivative [Line Items]
Weighted Average Hedge Price | $ / gal	0.96

[1] Contains a combined derivative instrument consisting of a fixed price swap and a sold option to extend or double the volumes. We have swaps in place for 2019 for 150,000 Mmbtu/day on which the counterparty can elect to extend the contract through December 2020 at a weighted average price of $2.81. In addition, we have swaps in place for November and December 2019 where, if the counterparty elects to double the volume, we would have additional swaps in place for 20,000 Mmbtu/day at a weighted average price of $3.20. In 2020, if the counterparty elects to double the volume, we would have additional swaps in place for 140,000 Mmbtu/day at a weighted average price of $2.78. In addition, for January through March 2020, we have additional swaps in place, if the counterparty elects to double the volume, we would have an additional 20,000 Mmbtu/day at a weighted average price of $3.20.