PENSION AND POSTRETIREMENT BENEFIT PLANS - Defined Contribution Plans (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
Dec. 31, 2020	Oct. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Other long-term liabilities for the supplemental retirement plan	$ 35		$ 37
Expenses under provisions of defined contribution and supplemental plans	$ 28	$ 4	$ 36	$ 35

This element represents the accrued liabilities for supplemental retirement benefit plan which provides restoration of benefit lost due to government limitations on qualified retirement benefits.

No definition available.

Name:	crc_SupplementalRetirementPlanSupplementalRetirementPlanAccruedLiabilities
Namespace Prefix:	crc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant