INVESTMENTS - Information Regarding Changes in Unrealized Gains and Losses from Investments (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Changes in unrealized gains (losses):
Changes in unrealized gains (losses)	$ 2,399	$ 5,852	$ (3,142)
Financing Receivable, Troubled Debt Restructuring	0
Fixed maturity securities \| Available-for-sale securities
Changes in unrealized gains (losses):
Changes in unrealized gains (losses)	$ 2,399	$ 5,852	$ (3,142)

Amount of financing receivable modified as troubled debt restructuring.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

Name:	us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant