Investments - Net Investment Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 496	$ 383	$ 980	$ 832
Investment expenses	(12)	(11)	(24)	(21)
Net investment income (excluding net realized capital losses)	484	372	956	811
Net realized capital losses	(90)	(98)	(108)	(203)
Net investment income	394	274	848	608
Yield-related impairment losses	28	37	38	61
Credit-related impairment losses (reversal of losses)	0	(2)	0	(3)
Supporting experience-rated products
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Net investment income	8	9	16	17
Debt securities
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	265	204	509	395
Mortgage loans
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	19	14	36	27
Other investments
Schedule of Investment Income, Reported Amounts, by Category [Line Items]
Gross investment income	$ 212	$ 165	$ 435	$ 410