Investments (Fixed Maturity Securities by Sector) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	$ 78,287	$ 69,483
Fixed maturity securities, allowance for credit losses	11	2
Fixed maturity securities, gross unrealized gains	8,701	11,961
Fixed maturity securities, gross unrealized losses	450	143
Fixed maturity securities, estimated fair value	86,527	81,299
U.S. corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	34,773	32,062
Fixed maturity securities, allowance for credit losses	2	2
Fixed maturity securities, gross unrealized gains	3,890	5,286
Fixed maturity securities, gross unrealized losses	187	70
Fixed maturity securities, estimated fair value	38,474	37,276
Foreign corporate
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	10,813	9,926
Fixed maturity securities, allowance for credit losses	7	0
Fixed maturity securities, gross unrealized gains	902	1,493
Fixed maturity securities, gross unrealized losses	103	44
Fixed maturity securities, estimated fair value	11,605	11,375
RMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	8,838	7,578
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	433	644
Fixed maturity securities, gross unrealized losses	51	3
Fixed maturity securities, estimated fair value	9,220	8,219
U.S. government and agency
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	7,188	5,871
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	2,040	2,599
Fixed maturity securities, gross unrealized losses	60	6
Fixed maturity securities, estimated fair value	9,168	8,464
CMBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	6,890	6,120
Fixed maturity securities, allowance for credit losses	2	0
Fixed maturity securities, gross unrealized gains	329	586
Fixed maturity securities, gross unrealized losses	24	9
Fixed maturity securities, estimated fair value	7,193	6,697
State and political subdivision
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	3,937	3,607
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	829	948
Fixed maturity securities, gross unrealized losses	6	0
Fixed maturity securities, estimated fair value	4,760	4,555
ABS
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	4,255	2,831
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	34	60
Fixed maturity securities, gross unrealized losses	14	10
Fixed maturity securities, estimated fair value	4,275	2,881
Foreign government
Debt Securities, Available-for-sale [Line Items]
Fixed maturity securities, amortized cost	1,593	1,488
Fixed maturity securities, allowance for credit losses	0	0
Fixed maturity securities, gross unrealized gains	244	345
Fixed maturity securities, gross unrealized losses	5	1
Fixed maturity securities, estimated fair value	$ 1,832	$ 1,832

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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