INSURANCE LIABILITIES (Details - Reconciliation of change in net ultimates to prior year development) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	$ 137
Re-Attribution of ADC Recovery	0
Amortization of Deferred Gain at Inception	(211)
Prior Year Development	(74)
Total, prior years, excluding discount and amortization of deferred gain	(90)	$ (340)	$ 1,429
U.S. Workers Compensation
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	(322)
Re-Attribution of ADC Recovery	(9)
Amortization of Deferred Gain at Inception	(65)
Prior Year Development	(396)
Total, prior years, excluding discount and amortization of deferred gain	(367)	(699)	51
U.S. Excess Casualty
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	206
Re-Attribution of ADC Recovery	(60)
Amortization of Deferred Gain at Inception	(50)
Prior Year Development	96
Total, prior years, excluding discount and amortization of deferred gain	(149)	76	1,300
U.S. Other Casualty
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	(155)
Re-Attribution of ADC Recovery	(4)
Amortization of Deferred Gain at Inception	(48)
Prior Year Development	(207)
Total, prior years, excluding discount and amortization of deferred gain	(141)	168
U.S. Financial Lines
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	318
Re-Attribution of ADC Recovery	57
Amortization of Deferred Gain at Inception	(34)
Prior Year Development	341
Total, prior years, excluding discount and amortization of deferred gain	479	463	298
U.S. Property and Specialty Risks
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	(61)
Re-Attribution of ADC Recovery	25
Amortization of Deferred Gain at Inception	(12)
Prior Year Development	(48)
U.S. Personal Insurance
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	94
Re-Attribution of ADC Recovery	(9)
Amortization of Deferred Gain at Inception	(2)
Prior Year Development	83
Total, prior years, excluding discount and amortization of deferred gain	94	(96)	255
UK/Europe Casualty and Financial Lines
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	258
Re-Attribution of ADC Recovery	0
Amortization of Deferred Gain at Inception	0
Prior Year Development	258
Total, prior years, excluding discount and amortization of deferred gain	258	161	58
UK/Europe Property and Special Risks
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	(155)
Re-Attribution of ADC Recovery	0
Amortization of Deferred Gain at Inception	0
Prior Year Development	(155)
Total, prior years, excluding discount and amortization of deferred gain	(155)	(108)	(22)
UK/Europe and Japan Personal Insurance
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	(39)
Re-Attribution of ADC Recovery	0
Amortization of Deferred Gain at Inception	0
Prior Year Development	(39)
Total, prior years, excluding discount and amortization of deferred gain	(39)	$ (119)	$ (116)
Other Operations Run-Off
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	2
Re-Attribution of ADC Recovery	0
Amortization of Deferred Gain at Inception	0
Prior Year Development	2
Other Product Lines
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	(9)
Re-Attribution of ADC Recovery	0
Amortization of Deferred Gain at Inception	0
Prior Year Development	(9)
Asbestos LPT
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Development Ceded	1
Adverse Development Reinsurance
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Development Ceded	(228)
Adverse Development Reinsurance | U.S. Workers Compensation
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	49
Adverse Development Reinsurance | U.S. Excess Casualty
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	345
Adverse Development Reinsurance | U.S. Other Casualty
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	0
Adverse Development Reinsurance | U.S. Financial Lines
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	(134)
Adverse Development Reinsurance | U.S. Personal Insurance
Reconciliation Of Change In Net Ultimates To Prior Year Development [Line Items]
Prior Year Claims and Claims Adjustment Expense	$ 1