Commodity Derivative Positions (Detail)	Jun. 30, 2020 bbl $ / bbl
Crude Oil | Swap | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	51.17
Derivative, Nonmonetary Notional Amount | bbl	11,457
Crude Oil | Swap | Fourth Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	55.18
Derivative, Nonmonetary Notional Amount | bbl	9,804
Crude Oil | Swap | First Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	48.73
Derivative, Nonmonetary Notional Amount | bbl	6,667
Crude Oil | Swap | Second Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	48.73
Derivative, Nonmonetary Notional Amount | bbl	6,593
Crude Oil | 2-Way Collars [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	52.70
Derivative, Average Cap Price	58.26
Derivative, Nonmonetary Notional Amount | bbl	4,043
Crude Oil | 2-Way Collars [Domain] | Fourth Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	48.00
Derivative, Average Cap Price	57.10
Derivative, Nonmonetary Notional Amount | bbl	2,000
Crude Oil | 2-Way Collars [Domain] | First Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	47.50
Derivative, Average Cap Price	51.51
Derivative, Nonmonetary Notional Amount | bbl	3,333
Crude Oil | 2-Way Collars [Domain] | Second Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	47.50
Derivative, Average Cap Price	51.51
Derivative, Nonmonetary Notional Amount | bbl	3,297
Crude Oil | 2-Way Collars [Domain] | Third Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	40.00
Derivative, Average Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	3,261
Crude Oil | 2-Way Collars [Domain] | Fourth Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	40.00
Derivative, Average Cap Price	50.00
Derivative, Nonmonetary Notional Amount | bbl	3,261
Crude Oil | Purchased Puts Contract 1 [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	55.00
Derivative, Purchased Put Deferred Premium, Price	0.06
Derivative, Nonmonetary Notional Amount | bbl	2,174
Crude Oil | Purchased Puts Contract 2 [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	48.00
Derivative, Purchased Put Premium, Price	0.06
Derivative, Nonmonetary Notional Amount | bbl	674
Crude Oil | Purchased Puts Contract 3 [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	37.00
Derivative, Purchased Put Premium, Price	1.23
Derivative, Nonmonetary Notional Amount | bbl	2,174
Crude Oil | Purchased Puts Contract 4 [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	30.00
Derivative, Purchased Put Deferred Premium, Price	3.63
Derivative, Nonmonetary Notional Amount | bbl	2,717
Crude Oil | Purchased Puts Contract 5 [Domain] | First Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	36.00
Derivative, Purchased Put Premium, Price	4.50
Derivative, Nonmonetary Notional Amount | bbl	2,500
Crude Oil | Purchased Puts Contract 5 [Domain] | Second Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	36.00
Derivative, Purchased Put Premium, Price	4.50
Derivative, Nonmonetary Notional Amount | bbl	2,473
Crude Oil | Put Spread [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Put Spread Purchased Put, Price	39.00
Derivative, Put Spread Sold Put, Price	32.00
Derivative, Purchased Spread Deferred Premium, Price	3.25
Derivative, Nonmonetary Notional Amount | bbl	2,174
Crude Oil | Put Spread Contract 2 [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Put Spread Purchased Put, Price	30.00
Derivative, Put Spread Sold Put, Price	20.00
Derivative, Purchased Spread Deferred Premium, Price	2.45
Derivative, Nonmonetary Notional Amount | bbl	2,174
Crude Oil | Put Option | Fourth Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	43.50
Derivative, Nonmonetary Notional Amount | bbl	5,087
Crude Oil | Put Option | First Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	37.00
Derivative, Nonmonetary Notional Amount | bbl	10,833
Crude Oil | Put Option | Second Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	37.00
Derivative, Nonmonetary Notional Amount | bbl	10,714
Crude Oil | Put Option | Third Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	35.00
Derivative, Nonmonetary Notional Amount | bbl	3,261
Crude Oil | Put Option | Fourth Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	35.00
Derivative, Nonmonetary Notional Amount | bbl	3,261
Crude Oil | Basis Swap [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	1.04
Derivative, Nonmonetary Notional Amount | bbl	10,870
Crude Oil | CMA Roll Basis Swap [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, CMA Roll Basis Swap, Price	(0.45)
Derivative, Nonmonetary Notional Amount | bbl	10,870
MEH [Domain] | Swap | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	61.03
Derivative, Nonmonetary Notional Amount | bbl	2,000
MEH [Domain] | Swap | Fourth Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Swap Type, Average Fixed Price	61.03
Derivative, Nonmonetary Notional Amount | bbl	2,000
Natural Gas [Member] | 2-Way Collars [Domain] | Third Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	2.00
Derivative, Average Cap Price	2.21
Derivative, Nonmonetary Notional Amount | bbl	12,804
Natural Gas [Member] | 2-Way Collars [Domain] | Fourth Quarter 2020 [Member]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	2.00
Derivative, Average Cap Price	2.21
Derivative, Nonmonetary Notional Amount | bbl	12,804
Natural Gas [Member] | 2-Way Collars [Domain] | First Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	2.50
Derivative, Average Cap Price	2.85
Derivative, Nonmonetary Notional Amount | bbl	3,333
Natural Gas [Member] | 2-Way Collars [Domain] | Second Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	2.50
Derivative, Average Cap Price	2.85
Derivative, Nonmonetary Notional Amount | bbl	3,297
Natural Gas [Member] | 2-Way Collars [Domain] | Third Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	2.50
Derivative, Average Cap Price	2.85
Derivative, Nonmonetary Notional Amount | bbl	3,261
Natural Gas [Member] | 2-Way Collars [Domain] | Fourth Quarter 2021 [Domain]
Derivative Instruments Related to Oil and Gas Production [Line Items]
Derivative, Average Floor Price	2.50
Derivative, Average Cap Price	2.85
Derivative, Nonmonetary Notional Amount | bbl	3,261