Risk Management and Derivative Instruments - Open Commodity Positions (Detail)	6 Months Ended
	Jun. 30, 2021 MMBTU $ / MMBTU $ / bbl bbl
Natural Gas Derivative Contracts Fixed Price Swap Remaining 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	970,000
Weighted-average fixed price | $ / MMBTU	2.49
Natural Gas Derivative Two Way Collars Contracts Remaining 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	830,000
Weighted-average floor price	2.06
Weighted-average ceiling price	3.28
Natural Gas PEPL Basis Swaps Remaining Remaining 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	500,000
Weighted-average spread | $ / MMBTU	(0.40)
Crude Oil Derivative Contracts Fixed Price Swap Remaining 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	172,500
Weighted-average fixed price	49.37
Crude Oil Derivative Two Way Collars Contracts Remaining 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Crude Oil Derivative Three Way Collars Contracts Remaining 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	72,500
Weighted-average floor price	40.00
Weighted-average ceiling price	50.36
Weighted-average sub-floor price	30.00
NGL Derivative Contracts Fixed Price Swap Remaining 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	20,300
Weighted-average fixed price	23.74
Natural Gas Derivative Contracts Fixed Price Swap 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	695,000
Weighted-average fixed price | $ / MMBTU	2.56
Natural Gas Derivative Two Way Collars Contracts 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	595,000
Weighted-average floor price	2.37
Weighted-average ceiling price	3.09
Natural Gas PEPL Basis Swaps 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average spread | $ / MMBTU	0
Crude Oil Derivative Contracts Fixed Price Swap 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	99,000
Weighted-average fixed price	55.68
Crude Oil Derivative Two Way Collars Contracts 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	7,500
Weighted-average floor price	55.00
Weighted-average ceiling price	60.25
Crude Oil Derivative Three Way Collars Contracts 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	89,000
Weighted-average floor price	42.92
Weighted-average ceiling price	55.55
Weighted-average sub-floor price	32.58
NGL Derivative Contracts Fixed Price Swap 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average fixed price	0
Natural Gas Derivative Fixed Price Swaps 2023 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average fixed price | $ / MMBTU	0
Natural Gas Derivative Two Way Collar Contracts 2023 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	140,000
Weighted-average floor price	2.40
Weighted-average ceiling price	2.91
Natural Gas PEPL Basis Swaps 2023 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average spread | $ / MMBTU	0
Crude Oil Derivative Fixed Price Swaps 2023 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	55,000
Weighted-average fixed price	57.30
Crude Oil Derivative Two Way Collars Contracts 2023 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Crude Oil Derivative Three Way Collars Contracts 2023 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	30,000
Weighted-average floor price	55.00
Weighted-average ceiling price	67.15
Weighted-average sub-floor price	40.00
NGL Derivative Contracts Fixed Price Swap 2023 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average fixed price	0