Reinsurance - Summary of the impact of funds withheld (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Effects of Reinsurance [Line Items]
Total net investment income	$ 11,767	$ 14,612	$ 13,631
Total net realized gains (losses)	8,991	2,151	(2,238)
Income (loss) from continuing operations before income tax expense (benefit)	14,282	12,099	(7,293)
Income tax expense (benefit)	3,006	2,176	(1,460)
Net income (loss)	11,275	9,923	(5,829)
Change in unrealized depreciation of all other investments	1,392	1,889	735
Comprehensive income (loss)	(22,127)	4,093	2,684
Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Total net investment income	943	1,971	1,053
Fortitude Holdings
Effects of Reinsurance [Line Items]
Net underwriting income	0	0	0
Total net investment income	943	1,971	1,053
Total net realized gains (losses)	6,995	400	(2,182)
Income (loss) from continuing operations before income tax expense (benefit)	7,938	2,371	(1,129)
Income tax expense (benefit)	1,667	499	(237)
Net income (loss)	6,271	1,872	(892)
Comprehensive income (loss)	371	112	(80)
Fortitude Holdings | Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Total net realized gains (losses)	(486)	1,003	463
Fortitude Holdings | Fortitude Re funds withheld assets | Embedded derivatives
Effects of Reinsurance [Line Items]
Total net realized gains (losses)	7,481	(603)	(2,645)
Fortitude Holdings | Other investments
Effects of Reinsurance [Line Items]
Change in unrealized depreciation of all other investments	$ (5,900)	$ (1,760)	$ 812