Commodity Derivative Positions (Detail)	Dec. 31, 2020 bbl $ / bbl
First Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.00
Derivative, Cap Price	45.78
Derivative, Nonmonetary Notional Amount | bbl	9,722
First Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	2.607
Derivative, Cap Price	3.117
Derivative, Nonmonetary Notional Amount | bbl	10,000
First Quarter 2021 [Member] [Domain] | Put Option [Member] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	6,667
Derivative, Swap Type, Average Fixed Price	2.000
First Quarter 2021 [Member] [Domain] | Swap [Member] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	3,889
Derivative, Swap Type, Average Fixed Price	54.38
First Quarter 2021 [Member] [Domain] | Purchased Put [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	1,667
Derivative, Swap Type, Average Fixed Price	55.00
First Quarter 2021 [Member] [Domain] | Basis Swap [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	8,889
Derivative, Swap Type, Average Fixed Price	1.16
First Quarter 2021 [Member] [Domain] | CMA Roll Basis Swap [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	14,444
Derivative, CMA Roll Basis Swap, Price	(0.18)
First Quarter 2021 [Member] [Domain] | Sold Put [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	556
Derivative, Swap Type, Average Fixed Price	26.50
Second Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	42.84
Derivative, Cap Price	51.70
Derivative, Nonmonetary Notional Amount | bbl	10,440
Second Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	2.607
Derivative, Cap Price	3.117
Derivative, Nonmonetary Notional Amount | bbl	9,890
Second Quarter 2021 [Member] [Domain] | Put Option [Member] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	6,593
Derivative, Swap Type, Average Fixed Price	2.000
Second Quarter 2021 [Member] [Domain] | Swap [Member] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	3,297
Derivative, Swap Type, Average Fixed Price	55.89
Second Quarter 2021 [Member] [Domain] | CMA Roll Basis Swap [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	13,187
Derivative, CMA Roll Basis Swap, Price	0.07
Second Quarter 2021 [Member] [Domain] | Sold Put [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	11,538
Derivative, Swap Type, Average Fixed Price	36.93
Third Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.35
Derivative, Cap Price	51.85
Derivative, Nonmonetary Notional Amount | bbl	9,239
Third Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	2.607
Derivative, Cap Price	3.117
Derivative, Nonmonetary Notional Amount | bbl	9,783
Third Quarter 2021 [Member] [Domain] | Put Option [Member] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	6,522
Derivative, Swap Type, Average Fixed Price	2.000
Third Quarter 2021 [Member] [Domain] | Swap [Member] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	815
Derivative, Swap Type, Average Fixed Price	45.54
Third Quarter 2021 [Member] [Domain] | CMA Roll Basis Swap [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	13,043
Derivative, CMA Roll Basis Swap, Price	0.07
Third Quarter 2021 [Member] [Domain] | Sold Put [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	5,707
Derivative, Swap Type, Average Fixed Price	35.14
Fourth Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.40
Derivative, Cap Price	52.10
Derivative, Nonmonetary Notional Amount | bbl	8,152
Fourth Quarter 2021 [Member] [Domain] | 2-Way Collars [Domain] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	2.607
Derivative, Cap Price	3.117
Derivative, Nonmonetary Notional Amount | bbl	9,783
Fourth Quarter 2021 [Member] [Domain] | Put Option [Member] | Natural Gas [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	6,522
Derivative, Swap Type, Average Fixed Price	2.000
Fourth Quarter 2021 [Member] [Domain] | Swap [Member] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	815
Derivative, Swap Type, Average Fixed Price	45.54
Fourth Quarter 2021 [Member] [Domain] | CMA Roll Basis Swap [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	13,043
Derivative, CMA Roll Basis Swap, Price	0.07
Fourth Quarter 2021 [Member] [Domain] | Sold Put [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Nonmonetary Notional Amount | bbl	5,707
Derivative, Swap Type, Average Fixed Price	35.14
First Quarter 2022 [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.00
Derivative, Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	2,917
Second Quarter 2022 [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.00
Derivative, Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	2,885
Third Quarter 2022 [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.00
Derivative, Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	2,853
Fourth Quarter 2022 [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.00
Derivative, Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	2,853
First Quarter 2023 [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.00
Derivative, Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	2,917
Second Quarter 2023 [Domain] | 2-Way Collars [Domain] | Crude Oil
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Floor Price	40.00
Derivative, Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	2,855