Investments - Components of net investment income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net Investment Income [Line Items]
Total investment income	$ 2,819	$ 3,856	$ 8,988	$ 11,423
Investment expenses	151	141	479	376
Net investment income	2,668	3,715	8,509	11,047
Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	2,656	3,351	8,328	9,907
Investment expenses	143	131	453	348
Net investment income	2,513	3,220	7,875	9,559
Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	163	505	660	1,516
Investment expenses	8	10	26	28
Net investment income	155	495	634	1,488
Available for sale fixed maturity securities, including short-term investments
Net Investment Income [Line Items]
Total investment income	2,406	2,547	7,162	7,593
Available for sale fixed maturity securities, including short-term investments | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	2,150	2,173	6,338	6,481
Available for sale fixed maturity securities, including short-term investments | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	256	374	824	1,112
Other fixed maturity securities
Net Investment Income [Line Items]
Total investment income	(241)	35	(915)	32
Gains/(losses) recognized in earnings on hedging derivatives	(57)	(3)	(208)	(49)
Other fixed maturity securities | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	(73)	32	(449)	23
Other fixed maturity securities | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	(168)	3	(466)	9
Equity securities
Net Investment Income [Line Items]
Total investment income	16	(45)	(41)	(36)
Equity securities | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	16	(45)	(41)	(36)
Equity securities | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	0	0	0	0
Interest on mortgage and other loans
Net Investment Income [Line Items]
Total investment income	568	485	1,578	1,449
Interest on mortgage and other loans | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	515	435	1,428	1,295
Interest on mortgage and other loans | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	53	50	150	154
Alternative investments
Net Investment Income [Line Items]
Total investment income	(38)	693	867	2,005
Alternative investments | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	(49)	616	729	1,767
Alternative investments | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	11	77	138	238
Real estate
Net Investment Income [Line Items]
Total investment income	14	99	46	215
Real estate | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	14	99	46	215
Real estate | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	0	0	0	0
Other investments
Net Investment Income [Line Items]
Total investment income	94	42	291	165
Gains/(losses) recognized in earnings on hedging derivatives	62	9	194	52
Other investments | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	83	41	277	162
Other investments | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	$ 11	$ 1	$ 14	$ 3