Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

DIVESTITURES AND ACQUISITIONS - Bakersfield Office Building (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	10 Months Ended	12 Months Ended
	Apr. 30, 2018	Dec. 31, 2020	Oct. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Acquisition cost		$ 0	$ 0	$ 6	$ 547
Office building and land
Business Acquisition [Line Items]
Acquisition cost	$ 48