Fair Value Measurements - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Assets:
Bonds available for sale	$ 70,528	$ 71,032
Other bond securities	677	741
Equity securities	1,616	502
Derivative assets	339	338
Counterparty netting	(143)	(164)
Cash Collateral	$ (196)	$ (169)
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets	Other assets
Derivative assets	$ 0	$ 5
Short-term investments	8,196	11,141
Liabilities:
Derivative liabilities	412	465
Counterparty netting	(143)	(164)
Cash Collateral	$ (175)	$ (212)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities	Other Liabilities
Derivative liabilities	$ 94	$ 89
Fortitude Re funds withheld payable	(2,960)	(3,038)
Fair Value Using NAV Per Share (or its equivalent)	3,227	3,456
Corebridge Financial Inc
Assets:
Equity securities	607
Liabilities:
Corebridge retained investment		1,500
Onex Corporation
Assets:
Equity securities	548
U.S. government and government sponsored entities
Assets:
Bonds available for sale	2,316	3,298
Obligations of states, municipalities and political subdivisions
Assets:
Bonds available for sale	2,696	2,775
Non-U.S. governments
Assets:
Bonds available for sale	6,291	6,516
Corporate debt
Assets:
Bonds available for sale	37,802	37,235
RMBS
Assets:
Bonds available for sale	11,072	10,168
CMBS
Assets:
Bonds available for sale	4,636	4,616
CLO/ABS
Assets:
Bonds available for sale	5,715	6,424
Levels 1, 2 and 3
Assets:
Bonds available for sale	70,528	71,032
Other bond securities	677	741
Equity securities	1,616	502
Other invested assets	230	1,747
Short-term investments	4,877	5,909
Other assets		130
Total	77,928	80,066
Liabilities:
Fortitude Re funds withheld payable	(85)	(92)
Other liabilities	87	73
Total	96	70
Levels 1, 2 and 3 | U.S. government and government sponsored entities
Assets:
Bonds available for sale	2,316	3,298
Levels 1, 2 and 3 | Obligations of states, municipalities and political subdivisions
Assets:
Bonds available for sale	2,696	2,775
Other bond securities	50	51
Levels 1, 2 and 3 | Non-U.S. governments
Assets:
Bonds available for sale	6,291	6,516
Other bond securities	21	23
Levels 1, 2 and 3 | Corporate debt
Assets:
Bonds available for sale	37,802	37,235
Other bond securities	204	274
Levels 1, 2 and 3 | RMBS
Assets:
Bonds available for sale	11,072	10,168
Other bond securities	93	97
Levels 1, 2 and 3 | CMBS
Assets:
Bonds available for sale	4,636	4,616
Other bond securities	42	42
Levels 1, 2 and 3 | CLO/ABS
Assets:
Bonds available for sale	5,715	6,424
Other bond securities	267	254
Level 1
Assets:
Bonds available for sale	559	275
Other bond securities	0	0
Equity securities	1,559	446
Other invested assets	0	1,512
Derivative assets	0	0
Short-term investments	3,253	4,106
Other assets		0
Total	5,371	6,339
Liabilities:
Derivative liabilities	0	0
Fortitude Re funds withheld payable	0	0
Other liabilities	13	0
Total	13	0
Level 1 | U.S. government and government sponsored entities
Assets:
Bonds available for sale	450	209
Level 1 | Obligations of states, municipalities and political subdivisions
Assets:
Bonds available for sale	0	0
Other bond securities	0	0
Level 1 | Non-U.S. governments
Assets:
Bonds available for sale	109	66
Other bond securities	0	0
Level 1 | Corporate debt
Assets:
Bonds available for sale	0	0
Other bond securities	0	0
Level 1 | RMBS
Assets:
Bonds available for sale	0	0
Other bond securities	0	0
Level 1 | CMBS
Assets:
Bonds available for sale	0	0
Other bond securities	0	0
Level 1 | CLO/ABS
Assets:
Bonds available for sale	0	0
Other bond securities	0	0
Level 2
Assets:
Bonds available for sale	66,679	67,306
Other bond securities	510	571
Equity securities	3	1
Other invested assets	137	143
Derivative assets	314	312
Short-term investments	1,624	1,803
Other assets		0
Total	69,267	70,136
Liabilities:
Derivative liabilities	387	439
Fortitude Re funds withheld payable	0	0
Other liabilities	0	0
Total	387	439
Level 2 | U.S. government and government sponsored entities
Assets:
Bonds available for sale	1,866	3,089
Level 2 | Obligations of states, municipalities and political subdivisions
Assets:
Bonds available for sale	2,692	2,771
Other bond securities	50	51
Level 2 | Non-U.S. governments
Assets:
Bonds available for sale	6,175	6,427
Other bond securities	21	23
Level 2 | Corporate debt
Assets:
Bonds available for sale	37,717	37,122
Other bond securities	204	274
Level 2 | RMBS
Assets:
Bonds available for sale	9,586	8,622
Other bond securities	43	46
Level 2 | CMBS
Assets:
Bonds available for sale	4,611	4,592
Other bond securities	42	42
Level 2 | CLO/ABS
Assets:
Bonds available for sale	4,032	4,683
Other bond securities	150	135
Level 3
Assets:
Bonds available for sale	3,290	3,451
Other bond securities	167	170
Equity securities	54	55
Other invested assets	93	92
Derivative assets	25	26
Short-term investments	0	0
Other assets		130
Total	3,629	3,924
Liabilities:
Derivative liabilities	25	26
Fortitude Re funds withheld payable	(85)	(92)
Other liabilities	74	73
Total	14	7
Level 3 | U.S. government and government sponsored entities
Assets:
Bonds available for sale	0	0
Level 3 | Obligations of states, municipalities and political subdivisions
Assets:
Bonds available for sale	4	4
Other bond securities	0	0
Level 3 | Non-U.S. governments
Assets:
Bonds available for sale	7	23
Other bond securities	0	0
Level 3 | Corporate debt
Assets:
Bonds available for sale	85	113
Other bond securities	0	0
Level 3 | RMBS
Assets:
Bonds available for sale	1,486	1,546
Other bond securities	50	51
Level 3 | CMBS
Assets:
Bonds available for sale	25	24
Other bond securities	0	0
Level 3 | CLO/ABS
Assets:
Bonds available for sale	1,683	1,741
Other bond securities	117	119
Fair Value Measured at Net Asset Value Per Share
Liabilities:
Fair Value Using NAV Per Share (or its equivalent)	$ 3,100	$ 3,300