Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	$ 117	$ (606)	$ (443)	$ (414)
Net derivative gains (losses)	(378)	(123)	(88)	(535)
Net investment income	4,486	4,295	12,704	12,909
Income (loss) from discontinued operations, net of income tax	0	(968)	0	(986)
Other expenses	3,469	3,318	10,319	9,869
Income (loss) from continuing operations before provision for income tax	1,079	485	3,836	2,575
Provision for income tax expense (benefit)	164	(398)	770	(116)
Net income (loss)	915	(85)	3,066	1,705
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	(101)	411	(411)	681
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)	101	303	(36)	386
Net derivative gains (losses)	(80)	55	(71)	(89)
Net investment income	9	(1)	9	0
Income (loss) from continuing operations before provision for income tax	30	360	(98)	211
Provision for income tax expense (benefit)	7	126	(22)	73
Net income (loss)	23	234	(76)	138
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	(4)	307	(309)	965
Provision for income tax expense (benefit)	96	107	(47)	336
Net income (loss)	(100)	200	(262)	629
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	9	18	23
Net investment income	4	5	13	12
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)	(3)	(1)	0	(5)
Net investment income	1	0	2	2
Other expenses	0	0	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)	(6)	294	(342)	915
Net investment income	(1)	0	(2)	(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	0	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)	(37)	(46)	(108)	(143)
Amortization of prior service (costs) credit	6	6	15	18
Income (loss) from continuing operations before provision for income tax	(31)	(40)	(93)	(125)
Provision for income tax expense (benefit)	(7)	(17)	(20)	(39)
Net income (loss)	(24)	(23)	(73)	(86)
Brighthouse Financial, Inc
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of income tax		(968)		(986)
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	3	0	(86)
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	0	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	0	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	$ 0	$ 0	$ 11