Equity (Reclassifications Out of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	$ (333)	$ 88
Net investment income	3,745	4,421
Net derivative gains (losses)	349	(212)
Income (loss) from discontinued operations, net of income tax	0	(76)
Other expenses	(3,365)	(3,268)
Income (loss) from continuing operations before provision for income tax	1,656	1,072
Provision for income tax expense (benefit)	(399)	(120)
Net income (loss)	1,257	876
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss)	79	(11)
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)	40
Net investment income	3	6
Net derivative gains (losses)	53	(151)
Income (loss) from continuing operations before provision for income tax	(45)	(196)
Provision for income tax expense (benefit)	10	75
Net income (loss)	(35)	(121)
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	165	229
Provision for income tax expense (benefit)	(27)	(80)
Net income (loss)	138	149
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 investment income	3	4
Net derivative gains (losses)	16	8
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 investment income	1	0
Net derivative gains (losses)	5	(4)
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)	139	208
Other expenses	1	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)	(36)	(49)
Amortization of prior service (costs) credit	5	5
Income (loss) from continuing operations before provision for income tax	(31)	(44)
Provision for income tax expense (benefit)	7	5
Net income (loss)	(24)	(39)
Brighthouse Financial, Inc
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)	(168)
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	(91)
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
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	1
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	$ 10