Risk Management and Derivative Instruments - Open Commodity Positions (Detail)	9 Months Ended
	Sep. 30, 2019 MMBTU $ / MMBTU $ / bbl bbl
Natural Gas Derivative Contracts Fixed Price Swap 2022 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average fixed price | $ / MMBTU	0
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 PEPL Basis Swaps 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average fixed price	0
NGL Derivative Contracts Fixed Price Swap 2022 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average fixed price	0
Crude Oil 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
Natural Gas Derivative Contracts Fixed Price Swap 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	187,500
Weighted-average fixed price | $ / MMBTU	2.56
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
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
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 Two Way Collars Contracts 2021 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	0
Weighted-average floor price	0
Weighted-average ceiling price	0
Natural Gas PEPL Basis Swaps 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	500,000
Weighted-average fixed price	(0.40)
NGL Derivative Contracts Fixed Price Swap 2021 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	22,800
Weighted-average fixed price	24.25
Crude Oil Derivative Two 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
Natural Gas Derivative Contracts Fixed Price Swap 2020 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	150,000
Weighted-average fixed price | $ / MMBTU	2.65
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
Crude Oil Derivative Contracts Fixed Price Swap 2020 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	153,050
Weighted-average fixed price	57.54
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 Two Way Collars Contracts 2020 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	14,300
Weighted-average floor price	55.00
Weighted-average ceiling price	62.10
Natural Gas PEPL Basis Swaps 2020 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	600,000
Weighted-average fixed price	(0.46)
NGL Derivative Contracts Fixed Price Swap 2020 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	65,425
Weighted-average fixed price	25.20
Crude Oil Derivative Three Way Collars Contracts 2020 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	30,500
Weighted-average floor price	50.00
Weighted-average ceiling price	65.75
Weighted-average sub-floor price	40.00
Natural Gas Derivative Contracts Fixed Price Swap Remaining 2019 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	1,643,333
Weighted-average fixed price | $ / MMBTU	2.84
Natural Gas Derivative Two Way Collars Contracts Remaining 2019 [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 Remaining 2019 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	180,333
Weighted-average fixed price	55.25
Natural Gas Derivative Three Way Collars Contracts Remaining 2019 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	202,667
Weighted-average floor price	2.65
Weighted-average ceiling price	3.45
Weighted-average sub-floor price	2.15
Crude Oil Derivative Two Way Collars Contracts Remaining 2019 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	76,000
Weighted-average floor price	55.00
Weighted-average ceiling price	63.85
Natural Gas PEPL Basis Swaps 2019 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	0
Weighted-average fixed price	0
NGL Derivative Contracts Fixed Price Swap Remaining 2019 [Member]
Derivative [Line Items]
Average monthly volume (Bbls) | bbl	72,000
Weighted-average fixed price	29.96
Crude Oil Derivative Three Way Collars Contracts Remaining 2019 [Member]
Derivative [Line Items]
Average monthly volume (MMBtu) | MMBTU	61,200
Weighted-average floor price	53.75
Weighted-average ceiling price	63.14
Weighted-average sub-floor price	43.75