Investments (Evaluation of Fixed Maturity Securities AFS in an Unrealized Loss Position- Narrative) (Details) $ in Millions	9 Months Ended
Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 2,200
Equal to or Greater than 12 Months Gross Unrealized Loss	$ 789	$ 401
Percentage of gross unrealized loss	35.00%
Total number of securities in an unrealized loss position equal or greater than 12 months	793	690
Investment Grade
Debt Securities, Available-for-sale [Line Items]
Equal to or Greater than 12 Months Gross Unrealized Loss	$ 665	$ 350
Percentage of gross unrealized loss	84.00%
Total number of securities in an unrealized loss position equal or greater than 12 months	628
Below Investment Grade
Debt Securities, Available-for-sale [Line Items]
Equal to or Greater than 12 Months Gross Unrealized Loss	$ 124	$ 51
Percentage of gross unrealized loss	16.00%
Total number of securities in an unrealized loss position equal or greater than 12 months	165
Fixed maturity securities without an allowance for credit loss
Debt Securities, Available-for-sale [Line Items]
Change in Gross Unrealized Temporary Loss	$ 806

The percentage of gross unrealized loss for 12 months or greater.

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Amount of accumulated unrealized loss on 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 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount, before tax and after adjustment, of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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