Investments (Amortized Cost and Fair Value of Fixed Maturities by Contractual Maturities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis [Abstract]
Available-for-sale Securities, Debt Maturities, within One Year, Amortized Cost Basis	$ 1,641
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Amortized Cost Basis	9,698
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Amortized Cost Basis	10,969
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	26,731
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost	6,834
Available for Sale at Fair value - Amortized cost	55,873	$ 49,548
Available-for-sale Securities, Debt Maturities, Fair Value [Abstract]
Available-for-sale Securities, Debt Maturities, within One Year, Fair Value	1,649
Available-for-sale Securities, Debt Maturities, after One Through Five Years, Fair Value	10,115
Available-for-sale Securities, Debt Maturities, after Five Through Ten Years, Fair Value	11,700
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	30,381
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	6,904
Fixed maturity securities available-for-sale	$ 60,749	$ 56,735

Amortized cost of 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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