Investments (Evaluation of Available-For-Sale Securities for OTTI and Evaluating Temporarily Impaired AFS Securities - Narrative) (Details) $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($)
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 7,700
Fixed maturity securities without an allowance for credit loss
Debt Securities, Available-for-sale [Line Items]
Change in Gross Unrealized Temporary Loss	(6,100)
Twelve Months Or Greater
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 1,100
Percentage of gross unrealized loss	15.00%
Twelve Months Or Greater \| Investment Grade
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 919
Number of Securities	757
Percentage of gross unrealized loss	81.00%
Twelve Months Or Greater \| Below Investment Grade
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	$ 216
Number of Securities	190
Percentage of gross unrealized loss	19.00%

The percentage of gross unrealized loss.

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- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

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- Definition

Amount of 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

Amount before tax, after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

+ References

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- Definition

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.

+ References

No definition available.

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