Investments (Investment Income Net of Related Expenses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ 1,000	$ 890
Investment expense	(39)	(34)
Investment income, net of related expenses	961	856
Available-for-sale Securities [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	760	645
Equity securities
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	2	2
Mortgage Loans on Real Estate [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	90	74
Policy loans
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	14	13
Funds withheld at interest
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	89	72
Short-term Investments [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	34	21
Partnership Interest
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	7	54
Other invested assets
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ 4	$ 9