Investments (Components of Net Investment Gains Losses) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Debt Securities, Available-for-sale [Line Items]
Changes In Estimated Fair Value Subsequent To Purchase For Equity Securities	$ 15		$ 12
Marketable Securities, Gain (Loss) [Abstract]
Fixed maturity securities AFS — net gains (losses) on sales and disposals (1)	123	$ 284	(18)	$ 325
Equity securities — net gains (losses) on sales and disposals	(58)	6	58	55
Change In Estimated Fair Value Of Equity Securities	76	0	(37)	0
Other net investment gains (losses):
Mortgage loans (1)	4	29	(32)	3
Real estate and real estate joint ventures	40	169	154	436
Other limited partnership interests	1	(33)	9	(51)
Other	12	29	(176)	(67)
Subtotal	181	475	(59)	677
Change In Estimated Fair Value Of Other Limited Partnership Interests And Real Estate Joint Ventures	12	0	6	0
Non-investment portfolio gains (losses) (3)	(76)	(1,081)	(390)	(1,091)
Total net investment gains (losses)	117	(606)	(443)	(414)
Consumer Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(1)	(4)	(1)	(4)
Finance Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(7)	0	(7)	0
Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(8)	(4)	(8)	(4)
Debt Security, Government, Non-US [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(9)	0	(9)	0
Residential Mortgage Backed Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(1)	0	(1)
State and political subdivision
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	0	0	(2)
Fixed Maturity Securities
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	(17)	(5)	(17)	(7)
Net investment gains (losses)	106	279	(35)	318
Equity Securities
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	(4)	0	(17)
Net investment gains (losses)	18	2	21	38
Nonredeemable Preferred Stock [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	0	0	0	(1)
Common Stock
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings	$ 0	(4)	0	(16)
Brighthouse Financial, Inc
Marketable Securities, Gain (Loss) [Abstract]
Fixed maturity securities AFS — net gains (losses) on sales and disposals (1)		276		276
Other net investment gains (losses):
Mortgage loans (1)		47		47
Non-investment portfolio gains (losses) (3)		1,016		1,016
Brighthouse Financial, Inc \| FVO Common Stock [Member]
Other net investment gains (losses):
Non-investment portfolio gains (losses) (3)		$ 45	$ (327)	$ 45

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Change In Estimated Fair Value Of Other Limited Partnership Interests And Real Estate Joint Ventures.

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Changes In Estimated Fair Value Subsequent To Purchase For Equity Securities Still Held As Of The End Of The Period Included In Net Income Gains (Losses).

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

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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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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.

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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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The net realized gains or losses on investments during the period, not including gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity.

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