Reinsurance - Summary of the impact of funds withheld (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Effects of Reinsurance [Line Items]
Total net investment income	$ 3,571	$ 2,604	$ 7,104	$ 5,841
Total net realized gains (losses)	(297)	2,632	(2,206)	6,211
Income (loss) from continuing operations before income tax expense (benefit)	1,867	3,925	1,636	9,639
Income tax expense (benefit)	176	845	32	1,999
Net income (loss)	1,691	3,079	1,604	7,639
Change in unrealized depreciation of all other investments			(531)	1,332
Comprehensive income (loss)	(47)	(9,538)	3,779	(18,089)
Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Total net investment income	291	188	737	479
Fortitude Holdings
Effects of Reinsurance [Line Items]
Total net investment income	291	188	737	479
Total net realized gains (losses)	42	2,690	(1,154)	5,868
Income (loss) from continuing operations before income tax expense (benefit)	333	2,878	(417)	6,347
Income tax expense (benefit)	70	605	(88)	1,333
Net income (loss)	263	2,273	(329)	5,014
Comprehensive income (loss)	4	117	(32)	220
Fortitude Holdings | Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Total net realized gains (losses)	(138)	(86)	(169)	(226)
Fortitude Holdings | Fortitude Re funds withheld assets | Embedded derivatives
Effects of Reinsurance [Line Items]
Total net realized gains (losses)	180	2,776	(985)	6,094
Fortitude Holdings | Other investments
Effects of Reinsurance [Line Items]
Change in unrealized depreciation of all other investments	$ (259)	$ (2,156)	$ 297	$ (4,794)