Fair Value Measurements - Changes in Level 3 Recurring Fair Value Measurements, Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative liabilities, net:
Fair Value Beginning of Period	$ (210)	$ (739)	$ (479)	$ (512)
Net Realized and Unrealized (Gains) Losses Included in Income	8	(43)	39	83
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	108	(126)	346	(479)
Gross Transfers In	0	0		0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	(94)	(908)	(94)	(908)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	36	83	55	16
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	$ 0	$ (23)	$ 0	$ (31)
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Adjusted Revenues	Adjusted Revenues	Adjusted Revenues	Adjusted Revenues
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Other comprehensive income (loss)	Other comprehensive income (loss)	Other comprehensive income (loss)	Other comprehensive income (loss)
Net realized gains/(losses)
Derivative liabilities, net:
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Realized Investment Gains (Losses)	Realized Investment Gains (Losses)	Realized Investment Gains (Losses)	Realized Investment Gains (Losses)
Derivative liabilities, net
Derivative liabilities, net:
Fair Value Beginning of Period	$ (183)	$ (684)	$ (453)	$ (583)
Net Realized and Unrealized (Gains) Losses Included in Income	(12)	29	40	15
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	156	(82)	374	(169)
Gross Transfers In	0	0	0	0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	(39)	(737)	(39)	(737)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	3	5	8	64
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	(23)	0	(31)
Net Realized and Unrealized (Gains) Losses Included in Income	(12)	29	40	15
Gross Transfers In			0
Interest rate contracts
Derivative liabilities, net:
Fair Value Beginning of Period	(128)	(355)	(406)	(311)
Net Realized and Unrealized (Gains) Losses Included in Income	(8)	26	61	84
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	133	(10)	342	(112)
Gross Transfers In	0	0	0	0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	(3)	(339)	(3)	(339)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	0	0	(3)	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	(21)	0	(29)
Foreign exchange contracts
Derivative liabilities, net:
Fair Value Beginning of Period	2	0	2	0
Net Realized and Unrealized (Gains) Losses Included in Income	(2)	2	(2)	2
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	0	0	0	0
Gross Transfers In	0	0	0	0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	0	2	0	2
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	0	0	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	(2)	0	(2)
Equity contracts
Derivative liabilities, net:
Fair Value Beginning of Period	(56)	(328)	(48)	(271)
Net Realized and Unrealized (Gains) Losses Included in Income	(2)	2	(18)	(69)
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	23	(73)	31	(59)
Gross Transfers In	0	0	0	0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	(35)	(399)	(35)	(399)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	2	4	10	63
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0	0	0
Other contracts
Derivative liabilities, net:
Fair Value Beginning of Period	(1)	(1)	(1)	(1)
Net Realized and Unrealized (Gains) Losses Included in Income	0	0	(1)	(1)
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	0	0	1	1
Gross Transfers In	0	0	0	0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	(1)	(1)	(1)	(1)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	1	1	1	1
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0	0	0
Fortitude Re funds withheld payable
Derivative liabilities, net:
Fair Value Beginning of Period	(119)	(167)	(148)	(41)
Net Realized and Unrealized (Gains) Losses Included in Income	(8)	(58)	1	82
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	(27)	(44)	(7)	(310)
Gross Transfers In	0	0	0	0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	(154)	(269)	(154)	(269)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	33	78	47	(48)
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0	0	0
Other Liabilities
Derivative liabilities, net:
Fair Value Beginning of Period	92	112	122	112
Net Realized and Unrealized (Gains) Losses Included in Income	28	(14)	(2)	(14)
Other Comprehensive Income (Loss)	0	0	0	0
Purchases, Sales, Issuances and Settlements, Net	(21)	0	(21)	0
Gross Transfers In	0	0	0	0
Gross Transfers Out	0	0	0	0
Other	0	0	0	0
Fair Value End of Period	99	98	99	98
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	0	0	0	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	$ 0	0	$ 0	0
Credit contracts
Derivative liabilities, net:
Fair Value Beginning of Period		0		0
Net Realized and Unrealized (Gains) Losses Included in Income		(1)		(1)
Other Comprehensive Income (Loss)		0		0
Purchases, Sales, Issuances and Settlements, Net		1		1
Gross Transfers In		0		0
Gross Transfers Out		0		0
Other		0		0
Fair Value End of Period		0		0
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period		0		0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period		$ 0		$ 0