Reinsurance - Summary of the impact of funds withheld (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Effects of Reinsurance [Line Items]
Total net investment income	$ 2,604	$ 3,675	$ 5,841	$ 7,332
Total net realized gains (losses)	3,392	(1,926)	7,811	1,324
Income from continuing operations before income tax expense (benefit)	4,321	147	10,156	4,875
Income tax expense (benefit)	928	(3)	2,107	795
Net income	3,392	150	8,048	4,080
Change in unrealized depreciation of all other investments			3,238	1,267
Comprehensive income (loss)	(9,375)	3,892	(18,367)	777
Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Total net investment income	188	507	479	993
Fortitude Holdings
Effects of Reinsurance [Line Items]
Net underwriting income	0	0	0	0
Total net investment income	188	507	479	993
Total net realized gains (losses)	2,690	(1,883)	5,868	672
Income from continuing operations before income tax expense (benefit)	2,878	(1,376)	6,347	1,665
Income tax expense (benefit)	605	(289)	1,333	350
Net income	2,273	(1,087)	5,014	1,315
Comprehensive income (loss)	117	(32)	220	30
Fortitude Holdings | Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Total net realized gains (losses)	(86)	173	(226)	346
Fortitude Holdings | Fortitude Re funds withheld assets | Embedded derivatives
Effects of Reinsurance [Line Items]
Total net realized gains (losses)	2,776	(2,056)	6,094	326
Fortitude Holdings | Other investments
Effects of Reinsurance [Line Items]
Change in unrealized depreciation of all other investments	$ (2,156)	$ 1,055	$ (4,794)	$ (1,285)