DERIVATIVES - MARKETING DERIVATIVES (Details)	12 Months Ended
	Dec. 31, 2020 $ / Barrel	Dec. 31, 2020 $ / MillionCubicFeet	Dec. 31, 2020 MMBbls	Dec. 31, 2020 Bcf	Dec. 31, 2019 $ / Barrel	Dec. 31, 2019 $ / MillionCubicFeet	Dec. 31, 2019 MMBbls	Dec. 31, 2019 Bcf
Marketing Derivatives | Not designated as hedging instruments
Outstanding commodity derivatives contracts not designated as hedging instruments
Weighted average sales price (in dollars per share)	46.05	2.58			60.60	2.17
Crude Oil & NGLs | Long position
Outstanding commodity derivatives contracts not designated as hedging instruments
Commodity contracts Volume (MMbbl or Bcf)							55
Crude Oil & NGLs | Short position
Outstanding commodity derivatives contracts not designated as hedging instruments
Commodity contracts Volume (MMbbl or Bcf)			31
Natural gas (in cubic feet) | Short position
Outstanding commodity derivatives contracts not designated as hedging instruments
Commodity contracts Volume (MMbbl or Bcf) | Bcf				117				128