Investments (Continuous Gross Unrealized Losses for Fixed Maturity Securities by Sector) (Details) $ in Millions	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	$ 14,583	$ 7,973
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	$ 933	$ 585
Fixed maturity securities in continuous unrealized loss position, less than 12 months, number of securities	2,172	1,339
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	$ 46,468	$ 51,190
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	$ 7,065	$ 6,462
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, number of securities	6,430	6,958
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	$ 7,799	$ 4,549
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	646	409
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	21,238	22,435
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	3,257	2,923
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	2,002	1,010
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	101	74
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	7,979	8,229
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	1,379	1,202
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	1,825	445
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	71	8
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	2,247	3,453
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	543	509
RMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	1,047	413
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	29	21
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	5,453	5,749
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	897	784
ABS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	721	572
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	4	3
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	1,793	3,355
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	93	128
CMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	479	411
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	26	33
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	5,482	5,713
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	500	568
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	653	460
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	55	31
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	1,605	1,636
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	295	267
Foreign government
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	57	113
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	1	6
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	671	620
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	$ 101	$ 81