Investments (Investment Income Net of Related Expenses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ 837	$ 836
Investment expense	(27)	(24)
Investment income, net of related expenses	810	812
Available-for-sale Securities [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	533	495
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	73	66
Policy loans
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	13	14
Funds withheld at interest
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	51	84
Short-term Investments [Member]
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	2	1
Partnership Interest
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	161	161
Other invested assets
Major Categories Of Investment Income Net of Expenses [Line Items]
Investment revenue	$ 2	$ 13