Fair Value Measurements - Changes in level 3 recurring fair value measurements, liabilities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Liabilities:
Fair Value Beginning of Period	$ 4,386	$ 15,176	$ 15,721
Net Realized and Unrealized (Gains) Losses Included in Income	(10,649)	(75)
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	(33)	(468)
Gross Transfers In		0
Other	(32)	0
Fair Value End of Period	4,386	15,176
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	11,444	4,054
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Gross Transfers Out	$ 5
Gross Transfers Out		$ (2)
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenues	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)
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]	Total net realized gains (losses)	Total net realized gains (losses)
Policyholder contract deposits
Liabilities:
Fair Value Beginning of Period	$ 7,105	$ 9,682	9,798
Net Realized and Unrealized (Gains) Losses Included in Income	(3,602)	(545)
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	1,025	484
Gross Transfers In	0	0
Other	0	0
Fair Value End of Period	7,105	9,682
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	3,857	1,860
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Gross Transfers Out	0	(55)
Policyholder contract deposits \| Net realized gains/(losses)
Liabilities:
Net Realized and Unrealized (Gains) Losses Included in Income	(3,602)	(545)
Derivative liabilities, net
Liabilities:
Net Realized and Unrealized (Gains) Losses Included in Income	434	(133)
Purchases, Sales, Issuances and Settlements, Net	(494)	(229)
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	(142)	100
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Fair Value Beginning of Period	(428)	(119)
Net Realized and Unrealized (Gains) Losses Included in Income	434	(133)
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	(494)	(229)
Gross Transfers In	(81)	0
Gross Transfers Out	5	53
Other	(32)	0
Fair Value End of Period	(596)	(428)
Derivative liabilities, net \| Net realized gains/(losses)
Liabilities:
Net Realized and Unrealized (Gains) Losses Included in Income	495	(74)
Interest rate contracts
Liabilities:
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	71	1
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Fair Value Beginning of Period	0	0
Net Realized and Unrealized (Gains) Losses Included in Income	9	(1)
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	(245)	1
Gross Transfers In	(81)	0
Gross Transfers Out	6	0
Other	0	0
Fair Value End of Period	(311)	0
Foreign exchange contracts
Liabilities:
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	(1)	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Fair Value Beginning of Period	(1)	(2)
Net Realized and Unrealized (Gains) Losses Included in Income	0	0
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	(1)
Equity contracts
Liabilities:
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	(246)	32
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Fair Value Beginning of Period	(444)	(151)
Net Realized and Unrealized (Gains) Losses Included in Income	487	(75)
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	(313)	(271)
Gross Transfers In	0	0
Gross Transfers Out	(1)	53
Other	0	0
Fair Value End of Period	(271)	(444)
Credit contracts
Liabilities:
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	(31)	1
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Fair Value Beginning of Period	30	42
Net Realized and Unrealized (Gains) Losses Included in Income	3	9
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	(1)	(21)
Gross Transfers In	0	0
Gross Transfers Out	0	0
Other	(32)	0
Fair Value End of Period	0	30
Other contracts
Liabilities:
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	65	66
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Fair Value Beginning of Period	(13)	(8)
Net Realized and Unrealized (Gains) Losses Included in Income	(65)	(66)
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	64	61
Gross Transfers In	0	0
Gross Transfers Out	0	0
Other	0	0
Fair Value End of Period	(14)	(13)
Fortitude Re funds withheld payable
Liabilities:
Fair Value Beginning of Period	(2,235)	5,922	$ 6,042
Net Realized and Unrealized (Gains) Losses Included in Income	(7,481)	603
Other Comprehensive Income (Loss)	0	0
Purchases, Sales, Issuances and Settlements, Net	(676)	(723)
Gross Transfers In	0	0
Other	0	0
Fair Value End of Period	(2,235)	5,922
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	7,729	2,094
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0	0
Derivative liabilities, net:
Gross Transfers Out	0	0
Fortitude Re funds withheld payable \| Net realized gains/(losses)
Liabilities:
Net Realized and Unrealized (Gains) Losses Included in Income	(7,481)	603
Other Liabilities
Liabilities:
Fair Value Beginning of Period	112	0
Net Realized and Unrealized (Gains) Losses Included in Income	0
Other Comprehensive Income (Loss)	0
Purchases, Sales, Issuances and Settlements, Net	112
Gross Transfers In	0
Other	0
Fair Value End of Period	112	$ 0
Changes in Unrealized Gains (Losses) Included in Income on Instruments Held at End of Period	0
Changes in Unrealized Gains (Losses) Included in Other Comprehensive Income (Loss) for Recurring Level 3 Instruments Held at End of Period	0
Derivative liabilities, net:
Gross Transfers Out	$ 0

Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis Liabilities, Other Increase (Decrease)

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of gain (loss) recognized in income from derivative asset (liability) after deduction of derivative liability (asset), measured at fair value on recurring basis using unobservable input (level 3).

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Amount of transfers of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) into level 3 of the fair value hierarchy.

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