Investments (Investment Income Net of Related Expenses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	$ 3,246	$ 2,667	$ 2,616
Investment Income, Investment Expense	(108)	(92)	(96)
Investment income, net of related expenses	3,138	2,575	2,520
Available-for-sale Securities [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	2,059	1,928	1,786
Equity Securities [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	5	6	8
Mortgage Loans on Real Estate [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	293	282	255
Policy Loans [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	55	56	58
Funds Withheld At Interest [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	351	279	297
Short-term Investments [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	3	7	28
Other Aggregated Investments [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	61	59	65
Partnership Interest [Member]
Major Categories Of Investment Income Net Of Expenses [Line Items]
Gross Investment Income, Operating	$ 419	$ 50	$ 119