Investments (Fair Values And Unrealized Losses By Investment Category And By The Duration Of The Securities' Continuous Unrealized Loss Position) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Investments, Unrealized Loss Position
Total Unrealized Losses	$ 687	$ 908
Corporate Securities
Investments, Unrealized Loss Position
Total Unrealized Losses	454	580
States, Municipalities and Political Subdivisions
Investments, Unrealized Loss Position
Total Unrealized Losses	208	303
Government-Sponsored Enterprises
Investments, Unrealized Loss Position
Total Unrealized Losses	6	3
United States Government
Investments, Unrealized Loss Position
Total Unrealized Losses	3	5
Mortgage-backed
Investments, Unrealized Loss Position
Total Unrealized Losses	16	16
Fixed Maturities
Investments, Unrealized Loss Position
Less than 12 months fair value	1,384	8,760
Less than 12 Months, Unrealized losses	18	706
12 months or more fair value	7,912	800
12 Months or more, unrealized losses	669	202
Total fair value	9,296	9,560
Total Unrealized Losses	687	908
Fixed Maturities | Corporate Securities
Investments, Unrealized Loss Position
Less than 12 months fair value	379	5,651
Less than 12 Months, Unrealized losses	13	412
12 months or more fair value	5,560	661
12 Months or more, unrealized losses	441	168
Total fair value	5,939	6,312
Total Unrealized Losses	454	580
Fixed Maturities | States, Municipalities and Political Subdivisions
Investments, Unrealized Loss Position
Less than 12 months fair value	313	2,600
Less than 12 Months, Unrealized losses	2	274
12 months or more fair value	1,932	77
12 Months or more, unrealized losses	206	29
Total fair value	2,245	2,677
Total Unrealized Losses	208	303
Fixed Maturities | Government-Sponsored Enterprises
Investments, Unrealized Loss Position
Less than 12 months fair value	652	123
Less than 12 Months, Unrealized losses	3	3
12 months or more fair value	113	3
12 Months or more, unrealized losses	3	0
Total fair value	765	126
Total Unrealized Losses	6	3
Fixed Maturities | United States Government
Investments, Unrealized Loss Position
Less than 12 months fair value	32	146
Less than 12 Months, Unrealized losses	0	3
12 months or more fair value	129	41
12 Months or more, unrealized losses	3	2
Total fair value	161	187
Total Unrealized Losses	3	5
Fixed Maturities | Mortgage-backed
Investments, Unrealized Loss Position
Less than 12 months fair value	5	215
Less than 12 Months, Unrealized losses	0	13
12 months or more fair value	172	14
12 Months or more, unrealized losses	16	3
Total fair value	177	229
Total Unrealized Losses	16	16
Fixed Maturities | Foreign government
Investments, Unrealized Loss Position
Less than 12 months fair value	3	25
Less than 12 Months, Unrealized losses	0	1
12 months or more fair value	6	4
12 Months or more, unrealized losses	0	0
Total fair value	9	29
Total Unrealized Losses	$ 0	$ 1