Investments (Components of Net Investment Gains (Losses)) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Net investment gains (losses), fixed maturity securities	$ 62	$ (65)	$ 47	$ (103)
Net investment gains (losses), equity securities	1	(2)	11	(3)
Net investment gains (losses), mortgage loans	(3)	(3)	(7)	(7)
Net investment gains (losses), real estate limited partnerships and limited liability companies	1	0	0	42
Net investment gains (losses), other limited partnership interests	(4)	0	(5)	0
Net investment gains (losses), other	(1)	(4)	0	(7)
Total net investment gains (losses)	$ 56	$ (74)	$ 46	$ (78)

The net gain (loss) resulting from sales and other disposals of other limited partnership interests.

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- Definition

Amount of realized and unrealized gain (loss) on investment.

+ References

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- Definition

The difference between the carrying value and the sale price of debt securities, not separately or otherwise categorized as trading, available-for-sale, or held-to-maturity. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale.

+ References

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The difference between the carrying value and the sale price of equity securities, not separately or otherwise categorized as trading or available-for-sale. This element includes investments in which the entity holds a small ownership stake (generally, less than 20% of the shares outstanding) and cannot exert significant influence.

+ References

No definition available.

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The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

+ References

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- Definition

The net gain (loss) resulting from a sale of loans, including adjustments to record loans classified as held-for-sale at the lower-of-cost-or-market and fair value adjustments to loan held for investment purposes.

+ References

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- Definition

The net gain (loss) resulting from sales and other disposals of real estate owned for investment purposes.

+ References

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