DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Derivative Instruments (Detail) bbl in Thousands, MMBTU in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2018 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 | $	$ 27
Put Options | April—December 2018 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	2,750
Derivative, weighted average strike price (USD per bbl) | $ / bbl	50.00
Put Options | July—December 2018 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	5,520
Derivative, weighted average strike price (USD per bbl) | $ / bbl	58.00
Put Options | July—December 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	5,520
Derivative, weighted average strike price (USD per bbl) | $ / bbl	53.00
Collars | April—December 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	5,088
Derivative, weighted average floor price (USD per bbl)	45.00
Derivative, weighted average ceiling price (USD per bbl)	57.00
Collars | April—June 2018 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	1,092
Derivative, weighted average floor price (USD per bbl)	50.00
Derivative, weighted average ceiling price (USD per bbl)	58.77
Collars | April—June 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	1,365
Derivative, weighted average floor price (USD per bbl)	45.00
Derivative, weighted average ceiling price (USD per bbl)	56.45
Call Options | Crude Oil
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative remaining unamortized premium paid | $	$ 8
Call Options | April—December 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	5,088
Derivative, weighted average strike price (USD per bbl) | $ / bbl	60.03
Fixed-Price Swaps | July—December 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, weighted average fixed price (USD per MMBtu)	2.96
Derivative, nonmonetary notional amount, energy measure | MMBTU	33,580
Fixed-Price Swaps | April—June 2018 | Crude Oil | Dated Brent
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	1,092
Derivative, weighted average fixed price (USD per MMBtu)	54.57
Fixed-Price Swaps | April—June 2018 | Crude Oil | NYMEX WTI
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, nonmonetary notional amount, volume (bbl) | bbl	1,365
Derivative, weighted average fixed price (USD per MMBtu)	51.23
Fixed-Price Swaps | April—June 2018 | Natural Gas | NYMEX Henry Hub
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative, weighted average fixed price (USD per MMBtu)	3.02
Derivative, nonmonetary notional amount, energy measure | MMBTU	28,210
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
Weighted Average Price Differential	(0.53)
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
Weighted Average Price Differential	(0.51)
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
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
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
Weighted Average Price Differential	(0.45)