DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Derivative Instruments (Detail) bbl in Thousands, $ in Millions	1 Months Ended	9 Months Ended
	Nov. 02, 2017 MMBTU $ / MMBTU $ / bbl bbl	Sep. 30, 2017 USD ($) MMBTU Counterparty $ / MMBTU $ / bbl bbl
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of derivative counterparties | Counterparty		14
Put Options | Crude Oil
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative remaining unamortized premium paid | $		$ 50
Put Options | October—December 2017 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		8,464
Derivative, weighted average strike price (USD per bbl) | $ / bbl		50.00
Put Options | October—December 2017 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		7,636
Derivative, weighted average strike price (USD per bbl) | $ / bbl		51.00
Put Options | January—December 2018 | Crude Oil | Dated Brent | Subsequent Event
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl	3,650
Derivative, weighted average strike price (USD per bbl) | $ / bbl	50
Fixed-Price Swaps | October—December 2017 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		4,370,000
Derivative, weighted average fixed price (USD per MMBtu)		3.32
Fixed-Price Swaps | January—June 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		2,715
Derivative, weighted average fixed price (USD per MMBtu)		51.23
Fixed-Price Swaps | January—June 2018 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		2,172
Derivative, weighted average fixed price (USD per MMBtu)		54.57
Fixed-Price Swaps | January—June 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		22,625,000
Derivative, weighted average fixed price (USD per MMBtu)		3.17
Fixed-Price Swaps | January - March 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		13,500,000
Derivative, weighted average fixed price (USD per MMBtu)		3.39
Fixed-Price Swaps | April—June 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		16,835,000
Derivative, weighted average fixed price (USD per MMBtu)		2.92
Fixed-Price Swaps | July - December 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		18,400,000
Derivative, weighted average fixed price (USD per MMBtu)		2.97
Fixed-Price Swaps | July - December 2018 | Natural Gas | NYMEX Henry Hub | Subsequent Event
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, weighted average fixed price (USD per MMBtu)	2.95
Fixed-Price Swaps | January—December 2018 | Natural Gas | NYMEX Henry Hub | Subsequent Event
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU	15,180,000
Collars | January—June 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		2,715
Derivative, weighted average floor price (USD per bbl)		45.00
Derivative, weighted average ceiling price (USD per bbl)		56.45
Collars | January—June 2018 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		2,172
Derivative, weighted average floor price (USD per bbl)		50.00
Derivative, weighted average ceiling price (USD per bbl)		58.77
Collars | January—December 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		6,023
Derivative, weighted average floor price (USD per bbl)		45.00
Derivative, weighted average ceiling price (USD per bbl)		57.02
Collars | January—December 2018 | Crude Oil | NYMEX WTI | Subsequent Event
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl	730
Derivative, weighted average floor price (USD per bbl)	45.00
Derivative, weighted average ceiling price (USD per bbl)	56.90
Call Options | Crude Oil
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative remaining unamortized premium paid | $		$ 9
Call Options | January—December 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume | bbl		6,023
Derivative, weighted average strike price (USD per bbl) | $ / bbl		60.00
Finanical Basis Swaps | January - March 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		9,450,000
Weighted Average Price Differential		(0.43)
Finanical Basis Swaps | October - December 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		1,380,000
Weighted Average Price Differential		(0.51)
Finanical Basis Swaps | July - December 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		33,120,000
Weighted Average Price Differential		(0.53)
Finanical Basis Swaps | January—March 2019 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		1,350,000
Weighted Average Price Differential		(0.54)
Finanical Basis Swaps | January—June 2019 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		32,580,000
Weighted Average Price Differential		(0.53)
Finanical Basis Swaps | January - December 2019 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, energy measure | MMBTU		14,600,000
Weighted Average Price Differential		(0.45)