Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	$ (227)	$ 104	$ (560)	$ 192
Net derivative gains (losses)	(59)	(200)	290	(412)
Net investment income	4,473	4,193	8,218	8,614
Income (loss) from discontinued operations, net of income tax	0	58	0	(18)
Other expenses	(3,485)	(3,283)	(6,850)	(6,551)
Income (loss) from continuing operations before provision for income tax	1,101	1,018	2,757	2,090
Provision for income tax expense (benefit)	(207)	(162)	(606)	(282)
Net income (loss)	894	914	2,151	1,790
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(389)	281	(310)	270
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Investment Gains (Losses), Net of Related Offsets
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	(36)	44	(137)	84
Net derivative gains (losses)	(44)	6	9	(145)
Net investment income	(3)	(5)	0	1
Income (loss) from continuing operations before provision for income tax	(83)	47	(128)	(149)
Provision for income tax expense (benefit)	19	(22)	29	53
Net income (loss)	(64)	25	(99)	(96)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from continuing operations before provision for income tax	(470)	429	(305)	658
Provision for income tax expense (benefit)	170	(149)	143	(229)
Net income (loss)	(300)	280	(162)	429
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest rate swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	1	6	17	14
Net investment income	6	3	9	7
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest rate forwards
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	(2)	0	3	(4)
Net investment income	0	2	1	2
Other expenses	1	1	1	1
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Foreign currency swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	(475)	413	(336)	621
Net investment income	(1)	(1)	(1)	(1)
Other expenses	0	0	1	1
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Credit forwards
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net derivative gains (losses)	0	1	0	1
Reclassification out of Accumulated Other Comprehensive Income | Defined Benefit Plans Adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of net actuarial gains (losses)	(35)	(48)	(71)	(97)
Amortization of prior service (costs) credit	4	7	9	12
Income (loss) from continuing operations before provision for income tax	(31)	(41)	(62)	(85)
Provision for income tax expense (benefit)	6	17	13	22
Net income (loss)	(25)	(24)	(49)	(63)
Brighthouse Financial, Inc | Reclassification out of Accumulated Other Comprehensive Income | Unrealized Investment Gains (Losses), Net of Related Offsets
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of income tax	0	2	0	(89)
Brighthouse Financial, Inc | Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest rate swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of income tax	0	1	0	2
Brighthouse Financial, Inc | Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Interest rate forwards
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of income tax	0	2	0	3
Brighthouse Financial, Inc | Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains (Losses) on Derivatives | Foreign currency swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of income tax	$ 0	$ 1	$ 0	$ 11