Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance beginning of period	$ 5,366	$ 4,767	$ 10,714
OCI before reclassifications	5,994	606	(8,764)
Deferred income tax benefit (expense)	(1,552)	(300)	2,418
AOCI before reclassifications, net of income tax	9,808	5,073	4,368
Amounts reclassified from AOCI	(1,147)	443	614
Deferred income tax benefit (expense)	400	(150)	(215)
Amounts reclassified from AOCI, net of income tax	(747)	293	399
Balance end of period	7,427	5,366	4,767
Unrealized Investment Gains (Losses), Net of Related Offsets
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance beginning of period	10,785	10,311	15,224
OCI before reclassifications	5,392	800	(7,224)
Deferred income tax benefit (expense)	(1,732)	(338)	2,456
AOCI before reclassifications, net of income tax	14,445	10,773	10,456
Amounts reclassified from AOCI	(289)	21	(223)
Deferred income tax benefit (expense)	87	(9)	78
Amounts reclassified from AOCI, net of income tax	(202)	12	(145)
Balance end of period	12,757	10,785	10,311
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance beginning of period	1,865	1,458	1,076
OCI before reclassifications	(140)	344	(19)
Deferred income tax benefit (expense)	47	(100)	6
AOCI before reclassifications, net of income tax	1,772	1,702	1,063
Amounts reclassified from AOCI	(1,025)	229	608
Deferred income tax benefit (expense)	356	(66)	(213)
Amounts reclassified from AOCI, net of income tax	(669)	163	395
Balance end of period	905	1,865	1,458
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance beginning of period	(5,312)	(4,950)	(3,303)
OCI before reclassifications	765	(476)	(1,646)
Deferred income tax benefit (expense)	125	114	(1)
AOCI before reclassifications, net of income tax	(4,422)	(5,312)	(4,950)
Amounts reclassified from AOCI	0	0	0
Deferred income tax benefit (expense)	0	0	0
Amounts reclassified from AOCI, net of income tax	0	0	0
Balance end of period	(4,390)	(5,312)	(4,950)
Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance beginning of period	(1,972)	(2,052)	(2,283)
OCI before reclassifications	(23)	(62)	125
Deferred income tax benefit (expense)	8	24	(43)
AOCI before reclassifications, net of income tax	(1,987)	(2,090)	(2,201)
Amounts reclassified from AOCI	167	193	229
Deferred income tax benefit (expense)	(43)	(75)	(80)
Amounts reclassified from AOCI, net of income tax	124	118	149
Balance end of period	(1,845)	$ (1,972)	$ (2,052)
Brighthouse Financial, Inc [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	(2,512)
Deferred income tax benefit (expense)	878
Amounts reclassified from AOCI, net of income tax	(1,634)
Brighthouse Financial, Inc [Member] | Unrealized Investment Gains (Losses), Net of Related Offsets
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	(2,286)
Deferred income tax benefit (expense)	800
Amounts reclassified from AOCI, net of income tax	(1,486)
Brighthouse Financial, Inc [Member] | Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	(305)
Deferred income tax benefit (expense)	107
Amounts reclassified from AOCI, net of income tax	(198)
Brighthouse Financial, Inc [Member] | Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	51
Deferred income tax benefit (expense)	(19)
Amounts reclassified from AOCI, net of income tax	32
Brighthouse Financial, Inc [Member] | Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	28
Deferred income tax benefit (expense)	(10)
Amounts reclassified from AOCI, net of income tax	$ 18