Investments (Sales or Disposals of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales or disposals of fixed maturity securities	$ 889	$ 1,371	$ 2,155	$ 8,007
Fixed maturity securities, gross investment gains	30	31	61	194
Fixed maturity securities, gross investment losses	(28)	(15)	(70)	(131)
Fixed maturity securities, net investment gains (losses)	$ 2	$ 16	$ (9)	$ 63

Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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-Publisher FASB
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Amount of cash inflow from sale 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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-Publisher FASB
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