Investments (Investment Income Net of Related Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	$ (4,612)	$ (3,755)	$ (3,288)
Investment Income, Investment Expense	(196)	(164)	(127)
Investment income, net of related expenses	4,416	3,591	3,161
Available-for-sale Securities [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	(3,541)	(2,753)	(2,305)
Equity Securities [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	(6)	(6)	(6)
Mortgage Loans on Real Estate [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	(401)	(324)	(298)
Policy Loans [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	(56)	(54)	(54)
Funds Withheld At Interest [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	(341)	(317)	(253)
Short-term Investments [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	(182)	(99)	(29)
Other Aggregated Investments [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	(11)	(21)	(12)
Partnership Interest [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	$ (96)	$ (181)	$ (331)