Investments - Components of net investment income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net Investment Income [Line Items]
Total investment income	$ 12,418	$ 15,134	$ 14,189
Investment expenses	651	522	558
Net investment income	11,767	14,612	13,631
Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	11,442	13,126	13,119
Investment expenses	618	485	541
Net investment income	10,824	12,641	12,578
Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	976	2,008	1,070
Investment expenses	33	37	17
Net investment income	943	1,971	1,053
Available for sale fixed maturity securities, including short-term investments
Net Investment Income [Line Items]
Total investment income	9,731	10,051	10,359
Available for sale fixed maturity securities, including short-term investments | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	8,664	8,583	9,508
Available for sale fixed maturity securities, including short-term investments | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	1,067	1,468	851
Other fixed maturity securities
Net Investment Income [Line Items]
Total investment income	(822)	(12)	553
Gains/(losses) recognized in earnings on hedging derivatives	(195)	(49)	195
Other fixed maturity securities | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	(363)	(19)	540
Other fixed maturity securities | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	(459)	7	13
Equity securities
Net Investment Income [Line Items]
Total investment income	(53)	(237)	200
Equity securities | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	(53)	(237)	200
Equity securities | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	0	0	0
Interest on mortgage and other loans
Net Investment Income [Line Items]
Total investment income	2,162	1,952	1,989
Interest on mortgage and other loans | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	1,959	1,745	1,883
Interest on mortgage and other loans | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	203	207	106
Alternative investments
Net Investment Income [Line Items]
Total investment income	989	2,900	1,012
Alternative investments | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	819	2,579	913
Alternative investments | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	170	321	99
Real estate
Net Investment Income [Line Items]
Total investment income	57	225	195
Real estate | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	57	225	195
Real estate | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	0	0	0
Other investments
Net Investment Income [Line Items]
Total investment income	354	255	(119)
Gains/(losses) recognized in earnings on hedging derivatives	186	65	(162)
Other investments | Excluding Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	359	250	(120)
Other investments | Fortitude Re Funds Withheld Assets
Net Investment Income [Line Items]
Total investment income	$ (5)	$ 5	$ 1