Risk Management and Derivative Instruments - Open Commodity Positions (Detail)	12 Months Ended
	Dec. 31, 2019 MMBTU $ / MMBTU $ / bbl bbl
Natural Gas Derivative Contracts Fixed Price Swap 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	300,000
Weighted-average fixed price | $ / MMBTU	2.46
Natural Gas Derivative Two Way Collars Contracts 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Crude Oil Derivative Contracts Fixed Price Swap 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	30,000
Weighted-average fixed price	55.32
Natural Gas Derivative Three Way Collars Contracts 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Weighted-average sub-floor price	0
Crude Oil Derivative Two Way Collars Contracts 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Natural Gas P E P L Basis Swaps Two Thousand Twenty Two
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average spread | $ / MMBTU	0
Crude Oil Derivative Three Way Collars Contracts 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Weighted-average sub-floor price	0
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 Contracts Fixed Price Swap 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	487,500
Weighted-average fixed price | $ / MMBTU	2.48
Natural Gas Derivative Two Way Collars Contracts 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	162,500
Weighted-average floor price	2.58
Weighted-average ceiling price	2.84
Natural Gas Derivative Three Way Collars Contracts 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Weighted-average sub-floor price	0
Crude Oil Derivative Three Way Collars Contracts 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Weighted-average sub-floor price	0
Natural Gas P E P L Basis Swaps Two Thousand Twenty One
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	500,000
Weighted-average spread | $ / MMBTU	(0.40)
Crude Oil Derivative Contracts Fixed Price Swap 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	116,250
Weighted-average fixed price	56.05
Crude Oil Derivative Two Way Collars Contracts 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average floor price	0
Weighted-average ceiling price	0
NGL Derivative Contracts Fixed Price Swap 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	22,800
Weighted-average fixed price	24.25
Natural Gas Derivative Contracts Fixed Price Swap 2020 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	600,000
Weighted-average fixed price | $ / MMBTU	2.53
Natural Gas Derivative Two Way Collars Contracts 2020 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	520,000
Weighted-average floor price	2.64
Weighted-average ceiling price	2.96
Natural Gas Derivative Three Way Collars Contracts 2020 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	76,000
Weighted-average floor price	2.65
Weighted-average ceiling price	3.45
Weighted-average sub-floor price	2.15
Crude Oil Derivative Three Way Collars Contracts 2020 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	30,500
Weighted-average floor price	50.00
Weighted-average ceiling price	65.75
Weighted-average sub-floor price	40.00
Natural Gas P E P L Basis Swaps Two Thousand Twenty
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	600,000
Weighted-average spread | $ / MMBTU	(0.46)
Crude Oil Derivative Contracts Fixed Price Swap 2020 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	213,050
Weighted-average fixed price	57.28
Crude Oil Derivative Two Way Collars Contracts 2020 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	14,300
Weighted-average floor price	55.00
Weighted-average ceiling price	62.10
NGL Derivative Contracts Fixed Price Swap 2020 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	65,425
Weighted-average fixed price	25.20