Investments (Continuous Gross Unrealized Losses for Fixed Maturity Securities by Sector) (Details) $ in Millions	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	$ 16,729	$ 3,323
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	$ 305	$ 83
Fixed maturity securities in continuous unrealized loss position, less than 12 months, number of securities	2,423	665
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	$ 1,658	$ 1,221
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	$ 145	$ 60
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, number of securities	368	241
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	$ 5,051	$ 1,726
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	111	57
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	887	181
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	76	13
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	2,016	243
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	60	7
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	305	345
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	43	37
RMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	3,481	180
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	50	2
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	32	22
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	1	1
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	1,712	236
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	40	6
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	222	0
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	20	0
CMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	1,390	331
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	21	7
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	95	44
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	3	2
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	347	46
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	6	0
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	6	0
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	0	0
ABS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	2,454	506
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	13	3
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	93	629
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	1	7
Foreign government
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities in continuous unrealized loss position, less than 12 months, estimated fair value	278	55
Fixed maturity securities in continuous unrealized loss position, less than 12 months, gross unrealized losses	4	1
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, estimated fair value	18	0
Fixed maturity securities in continuous unrealized loss position, 12 months or greater, gross unrealized losses	$ 1	$ 0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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