FAIR VALUE MEASUREMENTS (Details - Changes in Level 3 Recurring Fair Value Measurements) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	$ 30,958	$ 33,610
Net Realized and Unrealized Gains (Losses) Included in Income, assets	1,096	1,301
Other Comprehensive Income (Loss), assets	125	556
Purchases, Sales, Issuances and Settlements, Net, assets	(1,561)	(3,610)
Gross Transfers In, assets	4,289	2,448
Gross Transfers Out, assets	(3,291)	(3,347)
Divested Businesses	(38)	0
Reclassification of Held for Sale, assets		0
Fair Value End of Period, assets	31,578	30,958
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	71	180
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	276
Liabilities
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	6,808	4,269
Net realized and unrealized gains (losses) included in income, liabilities	5,222	1,749
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	14	790
Gross Transfers In, liabilities	(1)	0
Gross Transfers Out, liabilities	5	0
Divested Businesses	3,673	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	15,721	6,808
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	(2,852)	(1,140)
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Policyholder contract deposits
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	6,910	4,116
Net realized and unrealized gains (losses) included in income, liabilities	2,681	1,947
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	207	847
Gross Transfers In, liabilities	0	0
Gross Transfers Out, liabilities	0	0
Divested Businesses	0	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	9,798	6,910
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	(1,515)	(1,307)
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Derivative liabilities, net
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	(102)	153
Net realized and unrealized gains (losses) included in income, liabilities	(104)	(198)
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	83	(57)
Gross Transfers In, liabilities	(1)	0
Gross Transfers Out, liabilities	5	0
Divested Businesses	0	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	(119)	(102)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	40	167
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Interest rate contracts
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	0	15
Net realized and unrealized gains (losses) included in income, liabilities	(1)	3
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	1	(18)
Gross Transfers In, liabilities	0	0
Gross Transfers Out, liabilities	0	0
Divested Businesses	0	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	0	0
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	2	1
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Foreign exchange contracts
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	(6)	(5)
Net realized and unrealized gains (losses) included in income, liabilities	3	(7)
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	1	6
Gross Transfers In, liabilities	0	0
Gross Transfers Out, liabilities	0	0
Divested Businesses	0	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	(2)	(6)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	1	3
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Equity contracts
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	(151)	(75)
Net realized and unrealized gains (losses) included in income, liabilities	4	(43)
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	(8)	(33)
Gross Transfers In, liabilities	(1)	0
Gross Transfers Out, liabilities	5	0
Divested Businesses	0	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	(151)	(151)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	(33)	51
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Credit contracts
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	62	227
Net realized and unrealized gains (losses) included in income, liabilities	(47)	(84)
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	27	(81)
Gross Transfers In, liabilities	0	0
Gross Transfers Out, liabilities	0	0
Divested Businesses	0	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	42	62
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	8	46
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Other contracts
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	(7)	(9)
Net realized and unrealized gains (losses) included in income, liabilities	(63)	(67)
Other Comprehensive Income (Loss), liabilities	0	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	62	69
Gross Transfers In, liabilities	0	0
Gross Transfers Out, liabilities	0	0
Divested Businesses	0	0
Reclassified to Held for Sale, liabilities		0
Fair Value End of Year, liabilities	(8)	(7)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	62	66
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Fortitude Re funds withheld payable
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, liabilities	0
Net realized and unrealized gains (losses) included in income, liabilities	2,645
Other Comprehensive Income (Loss), liabilities	0
Purchases, Sales, Issuances and Settlements, Net, liabilities	(276)
Gross Transfers In, liabilities	0
Gross Transfers Out, liabilities	0
Divested Businesses	3,673
Fair Value End of Year, liabilities	6,042	0
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period, liabilities	(1,377)
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, liabilities	0
Bonds available for sale
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	25,931	27,093
Net Realized and Unrealized Gains (Losses) Included in Income, assets	695	835
Other Comprehensive Income (Loss), assets	122	554
Purchases, Sales, Issuances and Settlements, Net, assets	(704)	(1,107)
Gross Transfers In, assets	4,099	1,830
Gross Transfers Out, assets	(3,254)	(3,236)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		(38)
Fair Value End of Period, assets	26,889	25,931
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	276
Bonds available for sale | Obligations of states, municipalities and political subdivisions
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	2,121	2,000
Net Realized and Unrealized Gains (Losses) Included in Income, assets	7	(2)
Other Comprehensive Income (Loss), assets	211	247
Purchases, Sales, Issuances and Settlements, Net, assets	123	282
Gross Transfers In, assets	27	51
Gross Transfers Out, assets	(384)	(457)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		0
Fair Value End of Period, assets	2,105	2,121
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	208
Bonds available for sale | Non-U.S. governments
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	0	11
Net Realized and Unrealized Gains (Losses) Included in Income, assets	0	5
Other Comprehensive Income (Loss), assets	0	1
Purchases, Sales, Issuances and Settlements, Net, assets	4	(6)
Gross Transfers In, assets	7	5
Gross Transfers Out, assets	(6)	(16)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		0
Fair Value End of Period, assets	5	0
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	0
Bonds available for sale | Corporate debt
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	1,663	864
Net Realized and Unrealized Gains (Losses) Included in Income, assets	(110)	(7)
Other Comprehensive Income (Loss), assets	65	88
Purchases, Sales, Issuances and Settlements, Net, assets	11	(540)
Gross Transfers In, assets	1,482	1,513
Gross Transfers Out, assets	(762)	(255)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		0
Fair Value End of Period, assets	2,349	1,663
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	79
Bonds available for sale | Residential mortgage-backed securities (RMBS)
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	13,408	14,199
Net Realized and Unrealized Gains (Losses) Included in Income, assets	745	782
Other Comprehensive Income (Loss), assets	(337)	55
Purchases, Sales, Issuances and Settlements, Net, assets	(1,200)	(1,403)
Gross Transfers In, assets	29	83
Gross Transfers Out, assets	(951)	(287)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		(21)
Fair Value End of Period, assets	11,694	13,408
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	(172)
Bonds available for sale | Commercial mortgage-backed securities (CMBS)
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	1,053	917
Net Realized and Unrealized Gains (Losses) Included in Income, assets	18	24
Other Comprehensive Income (Loss), assets	60	47
Purchases, Sales, Issuances and Settlements, Net, assets	(1)	448
Gross Transfers In, assets	23	58
Gross Transfers Out, assets	(231)	(441)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		0
Fair Value End of Period, assets	922	1,053
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	55
Bonds available for sale | Collateralized Debt Obligations/Asset Backed Securities (CDO/ABS)
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	7,686	9,102
Net Realized and Unrealized Gains (Losses) Included in Income, assets	35	33
Other Comprehensive Income (Loss), assets	123	116
Purchases, Sales, Issuances and Settlements, Net, assets	359	112
Gross Transfers In, assets	2,531	120
Gross Transfers Out, assets	(920)	(1,780)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		(17)
Fair Value End of Period, assets	9,814	7,686
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	106
Other bond securities
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	3,738	5,845
Net Realized and Unrealized Gains (Losses) Included in Income, assets	302	446
Other Comprehensive Income (Loss), assets	0	0
Purchases, Sales, Issuances and Settlements, Net, assets	(1,342)	(2,443)
Gross Transfers In, assets	0	0
Gross Transfers Out, assets	0	(110)
Divested Businesses	0	0
Reclassification of Held for Sale, assets	0	0
Fair Value End of Period, assets	2,698	3,738
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	20	157
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	0
Other bond securities | Residential mortgage-backed securities (RMBS)
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	143	1,290
Net Realized and Unrealized Gains (Losses) Included in Income, assets	9	80
Other Comprehensive Income (Loss), assets	0	0
Purchases, Sales, Issuances and Settlements, Net, assets	(13)	(1,227)
Gross Transfers In, assets	0	0
Gross Transfers Out, assets	0	0
Divested Businesses	0	0
Reclassification of Held for Sale, assets	0	0
Fair Value End of Period, assets	139	143
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	5	2
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	0
Other bond securities | Commercial mortgage-backed securities (CMBS)
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	50	77
Net Realized and Unrealized Gains (Losses) Included in Income, assets	0	5
Other Comprehensive Income (Loss), assets	0	0
Purchases, Sales, Issuances and Settlements, Net, assets	(3)	(18)
Gross Transfers In, assets	0	0
Gross Transfers Out, assets	0	(14)
Divested Businesses	0	0
Reclassification of Held for Sale, assets	0	0
Fair Value End of Period, assets	47	50
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	(2)	6
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	0
Other bond securities | Collateralized Debt Obligations/Asset Backed Securities (CDO/ABS)
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	3,545	4,478
Net Realized and Unrealized Gains (Losses) Included in Income, assets	293	361
Other Comprehensive Income (Loss), assets	0	0
Purchases, Sales, Issuances and Settlements, Net, assets	(1,326)	(1,198)
Gross Transfers In, assets	0	0
Gross Transfers Out, assets	0	(96)
Divested Businesses	0	0
Reclassification of Held for Sale, assets	0	0
Fair Value End of Period, assets	2,512	3,545
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	17	149
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	0
Equity securities
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	8	27
Net Realized and Unrealized Gains (Losses) Included in Income, assets	(1)	0
Other Comprehensive Income (Loss), assets	6	0
Purchases, Sales, Issuances and Settlements, Net, assets	35	(20)
Gross Transfers In, assets	40	2
Gross Transfers Out, assets	(37)	(1)
Divested Businesses	0	0
Reclassification of Held for Sale, assets		0
Fair Value End of Period, assets	51	8
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	1
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	0
Other invested assets
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	1,192	587
Net Realized and Unrealized Gains (Losses) Included in Income, assets	100	20
Other Comprehensive Income (Loss), assets	(3)	2
Purchases, Sales, Issuances and Settlements, Net, assets	388	(33)
Gross Transfers In, assets	150	616
Gross Transfers Out, assets	0	0
Divested Businesses	0	0
Reclassification of Held for Sale, assets		0
Fair Value End of Period, assets	1,827	1,192
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	51	22
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	0
Other assets
Fair value assets and liabilities measured on recurring basis, unobservable input reconciliation calculation
Fair Value Beginning of Period, assets	89	58
Net Realized and Unrealized Gains (Losses) Included in Income, assets	0	0
Other Comprehensive Income (Loss), assets	0	0
Purchases, Sales, Issuances and Settlements, Net, assets	62	(7)
Gross Transfers In, assets	0	0
Gross Transfers Out, assets	0	0
Divested Businesses	(38)	0
Reclassification of Held for Sale, assets		38
Fair Value End of Period, assets	113	89
Changes in Unrealized Gains (Losses) Inlcuded in Income on Instruments Held at End of Period, assets	0	$ 0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period, assets	$ 0