Investments (Sales or Disposals of Fixed Maturity Securities) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales or disposals of fixed maturity securities	$ 619	$ 3,416	$ 1,266	$ 6,636
Fixed maturity securities, gross investment gains	14	99	31	163
Fixed maturity securities, gross investment losses	(36)	(37)	(42)	(116)
Fixed maturity securities, net investment gains (losses)	$ (22)	$ 62	$ (11)	$ 47

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
-Paragraph 9
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-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27357-111563

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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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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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
-Name Accounting Standards Codification
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-Section 45
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