Investments (Continuous Gross Unrealized Losses for Fixed Maturity Securities by Sector) (Details) $ in Millions	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	$ 7,973	$ 51,788
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	$ 585	$ 6,538
Fixed maturity securities in continuous unrealized loss position, less than 12 months, number of securities	1,339	7,261
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	$ 51,190	$ 11,815
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	$ 6,462	$ 2,836
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, number of securities	6,958	2,018
U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	$ 4,549	$ 24,163
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	409	3,279
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	22,435	3,915
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	2,923	1,157
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	1,010	8,219
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	74	1,407
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	8,229	1,560
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	1,202	505
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	445	3,037
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	8	259
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	3,453	1,146
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	509	337
RMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	413	4,693
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	21	489
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	5,749	2,245
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	784	447
ABS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	572	3,347
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	3	159
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	3,355	1,728
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	128	136
CMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	411	5,524
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	33	534
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	5,713	961
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	568	165
State and political subdivision
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	460	2,026
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	31	313
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	1,636	239
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	267	81
Foreign government
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	113	779
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	6	98
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	620	21
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	$ 81	$ 8