Reinsurance - Summary of the Impact of Funds Withheld (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Effects of Reinsurance [Line Items]
Total net investment income	$ 990	$ 837	$ 1,969	$ 1,681
Net realized gains (losses)	(180)	(14)	(267)	(525)
Income from continuing operations before income tax expense	617	886	1,675	1,288
Income tax expense	142	45	403	110
Net income (loss)	(3,884)	1,691	(2,284)	1,604
Change in unrealized depreciation of all other investments			349	33
Comprehensive income (loss)	2,810	(47)	3,353	3,779
Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Total net investment income	33	25	72	77
Fortitude Holdings
Effects of Reinsurance [Line Items]
Total net investment income	33	25	72	77
Net realized gains (losses)	7	51	(21)	(143)
Income from continuing operations before income tax expense	40	76	51	(66)
Income tax expense	9	16	11	(14)
Net income (loss)	31	60	40	(52)
Comprehensive income (loss)	(3)	2	(2)	(36)
Fortitude Holdings | Fortitude Re funds withheld assets
Effects of Reinsurance [Line Items]
Net realized gains (losses)	(1)	(7)	(20)	(61)
Fortitude Holdings | Fortitude Re funds withheld assets | Embedded derivatives
Effects of Reinsurance [Line Items]
Net realized gains (losses)	8	58	(1)	(82)
Fortitude Holdings | Other investments
Effects of Reinsurance [Line Items]
Change in unrealized depreciation of all other investments	$ (34)	$ (58)	$ (42)	$ 16