Investments (Net Investment Gains Losses - Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Debt Securities, Available-for-sale [Line Items]
Gains (losses) from foreign currency transactions	$ (47)	$ (118)	$ 18	$ (38)
Gain (Loss) on Sales of Loans, Net	(15)	(14)	(36)	(26)
Non-investment portfolio gains (losses) (2)	(238)	(113)	(314)	(10)
Gain (Loss) on Sale of Debt Investments	(46)	$ 45	(141)	$ 43
FVO Common Stock \| Brighthouse Financial, Inc
Debt Securities, Available-for-sale [Line Items]
Non-investment portfolio gains (losses) (2)	$ (159)		$ (327)

Amount before tax of foreign currency transaction realized gain (loss) recognized in the income statement.

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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.

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Amount of gain (loss) on sale or disposal of other assets.

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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.

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