Investments (Net Investment Income) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net Investment Income [Line Items]
Gross investment income	$ 1,349	$ 1,264	$ 4,020	$ 3,652
Less: Investment expenses	91	90	263	271
Net investment income	1,258	1,174	3,757	3,381
Fixed maturity securities
Net Investment Income [Line Items]
Gross investment income	941	886	2,777	2,577
Equity securities
Net Investment Income [Line Items]
Gross investment income	0	1	2	2
Mortgage loans
Net Investment Income [Line Items]
Gross investment income	252	240	747	715
Policy loans
Net Investment Income [Line Items]
Gross investment income	12	11	35	33
Limited partnerships and LLCs
Net Investment Income [Line Items]
Gross investment income	56	52	228	128
Cash, cash equivalents and short-term investments
Net Investment Income [Line Items]
Gross investment income	63	50	157	133
Other assets
Net Investment Income [Line Items]
Gross investment income	$ 25	$ 24	$ 74	$ 64

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