Investments (Investment Income Net of Related Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ 1,531	$ 1,228	$ 4,280	$ 3,359
Investment expense	(56)	(40)	(165)	(128)
Investment income, net of related expenses	1,475	1,188	4,115	3,231
Available-for-sale Securities [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	1,221	933	3,393	2,574
Equity securities
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	2	2	5	5
Mortgage Loans on Real Estate [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	144	103	391	290
Policy loans
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	44	14	74	42
Funds withheld at interest
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	81	88	215	253
Short-term Investments [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	42	48	123	126
Partnership Interest
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	0	46	88	74
Other invested assets
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ (3)	$ (6)	$ (9)	$ (5)