DEBT - 2014 Revolving Credit Facility (Details) $ in Millions	1 Months Ended	12 Months Ended
	Nov. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) item	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)
Debt
Percentage of lenders to approve decreases or affirmations in borrowing base		67.00%
2014 Revolving Credit Facility (Shared First Priority Lien)
Debt
Maximum borrowing capacity		$ 1,000
Increase to maximum borrowing capacity with lender approval		50
Available borrowing capacity, subject to minimum liquidity requirement		317
Financial covenant minimum month end liquidity		$ 150
Commitment fees on unused portion of the Revolving Credit Facility		0.50%
Borrowing base	$ 2,300
Number of consecutive redeterminations between which CRC or lenders can request a special redetermination | item		3
Financial covenants
Amount of cash on hand above which amounts owed under the Revolving Credit Facility must be repaid		$ 150
Minimum interest coverage ratio		1.20	1.20
Minimum asset coverage ratio		1.20	1.20
Other covenants
Amount of cash on hand above which amounts owed under the Revolving Credit Facility must be repaid		$ 150
2014 Revolving Credit Facility (Shared First Priority Lien) | Minimum
Debt
Percentage of lenders to approve increases in borrowing base		80.00%
Percentage of lenders to approve decreases or affirmations in borrowing base		67.00%
Percentage of lenders to request special redetermination in borrowing base		67.00%
2014 Revolving Credit Facility (Shared First Priority Lien) | Alternative Base Rate Loan Federal fund rate
Debt
Interest rate added to variable rate basis (as a percent)		0.50%
2014 Revolving Credit Facility (Shared First Priority Lien) | Alternative Base Rate Loan One-Month LIBOR
Debt
Interest rate added to variable rate basis (as a percent)		1.00%
2014 Revolving Credit Facility (Shared First Priority Lien) | Applicable margin on LIBOR loans | Minimum
Debt
Interest rate added to variable rate basis (as a percent)		3.25%	3.25%
2014 Revolving Credit Facility (Shared First Priority Lien) | Applicable margin on LIBOR loans | Maximum
Debt
Interest rate added to variable rate basis (as a percent)		4.00%	4.00%
2014 Revolving Credit Facility (Shared First Priority Lien) | Applicable margin on Alternate Base Rate loans | Minimum
Debt
Interest rate added to variable rate basis (as a percent)		2.25%	2.25%
2014 Revolving Credit Facility (Shared First Priority Lien) | Applicable margin on Alternate Base Rate loans | Maximum
Debt
Interest rate added to variable rate basis (as a percent)		3.00%	3.00%
2014 Revolving Credit Facility (Shared First Priority Lien) | Through 2019
Financial covenants
Maximum leverage ratio		1.90	1.90
2014 Revolving Credit Facility (Shared First Priority Lien) | After 2019
Financial covenants
Maximum leverage ratio		1.50	1.50
2014 Revolving Credit Facility (Shared First Priority Lien) | Up to $500 million
Other covenants
Percent of net cash proceeds from non-borrowing base asset sales that must be used to repay the 2014 RCF		25.00%
Net cash proceeds from non-borrowing base asset sales that are subject to percentage of repayment of the 2014 RCF		$ 500
2014 Revolving Credit Facility (Shared First Priority Lien) | $500 million and $1 billion
Other covenants
Percent of net cash proceeds from non-borrowing base asset sales that must be used to repay the 2014 RCF		50.00%
2014 Revolving Credit Facility (Shared First Priority Lien) | $500 million and $1 billion | Minimum
Other covenants
Net cash proceeds from non-borrowing base asset sales that are subject to percentage of repayment of the 2014 RCF		$ 500
2014 Revolving Credit Facility (Shared First Priority Lien) | $500 million and $1 billion | Maximum
Other covenants
Net cash proceeds from non-borrowing base asset sales that are subject to percentage of repayment of the 2014 RCF		$ 1,000
2014 Revolving Credit Facility (Shared First Priority Lien) | In excess of $1 billion
Other covenants
Percent of net cash proceeds from non-borrowing base asset sales that must be used to repay the 2014 RCF		75.00%
Net cash proceeds from non-borrowing base asset sales that are subject to percentage of repayment of the 2014 RCF		$ 1,000
2014 Revolving Credit Facility (Shared First Priority Lien) | Applications of proceeds from sale of nonborrowing base assets after required payment of 2014 RCF.
Other covenants
Amount of minimum liquidity to be maintained using proceeds from non-borrowing base asset sales to repurchase senior notes or second lien notes				$ 300
2014 Revolving Credit Facility (Shared First Priority Lien) | Letters of Credit
Debt
Maximum sub-limit on borrowing capacity for issuance of letters of credit		400
Letters of credit outstanding amount		$ 165	$ 162