Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ 8,436	$ 14,632	$ 5,347	$ 4,771
OCI before reclassifications	832	(1,300)	5,556	12,905
Deferred income tax benefit (expense)	(218)	404	(1,583)	(3,835)
AOCI before reclassifications, net of income tax	9,050	13,736	9,320	13,841
Amounts reclassified from AOCI	(627)	(221)	(1,051)	(368)
Deferred income tax benefit (expense)	216	80	370	122
Amounts reclassified from AOCI, net of income tax	(411)	(141)	(681)	(246)
Balance, end of period	7,005	13,595	7,005	13,595
Unrealized Investment Gains (Losses), Net of Related Offsets
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	13,469	18,204	10,766	10,315
OCI before reclassifications	803	(1,066)	4,826	10,872
Deferred income tax benefit (expense)	(270)	281	(1,686)	(3,656)
AOCI before reclassifications, net of income tax	14,002	17,419	13,906	17,531
Amounts reclassified from AOCI	(360)	(173)	(211)	(339)
Deferred income tax benefit (expense)	126	60	73	114
Amounts reclassified from AOCI, net of income tax	(234)	(113)	(138)	(225)
Balance, end of period	12,282	17,306	12,282	17,306
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	1,569	2,431	1,865	1,458
OCI before reclassifications	(166)	(24)	37	1,472
Deferred income tax benefit (expense)	56	8	(14)	(460)
AOCI before reclassifications, net of income tax	1,459	2,415	1,888	2,470
Amounts reclassified from AOCI	(307)	(94)	(965)	(174)
Deferred income tax benefit (expense)	107	30	336	55
Amounts reclassified from AOCI, net of income tax	(200)	(64)	(629)	(119)
Balance, end of period	1,061	2,351	1,061	2,351
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(4,679)	(4,020)	(5,312)	(4,950)
OCI before reclassifications	193	49	710	809
Deferred income tax benefit (expense)	(6)	30	110	200
AOCI before reclassifications, net of income tax	(4,492)	(3,941)	(4,492)	(3,941)
Amounts reclassified from AOCI	0	0	0	0
Deferred income tax benefit (expense)	0	0	0	0
Amounts reclassified from AOCI, net of income tax	0	0	0	0
Balance, end of period	(4,460)	(3,941)	(4,460)	(3,941)
Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(1,923)	(1,983)	(1,972)	(2,052)
OCI before reclassifications	2	(259)	(17)	(248)
Deferred income tax benefit (expense)	2	85	7	81
AOCI before reclassifications, net of income tax	(1,919)	(2,157)	(1,982)	(2,219)
Amounts reclassified from AOCI	40	46	125	145
Deferred income tax benefit (expense)	(17)	(10)	(39)	(47)
Amounts reclassified from AOCI, net of income tax	23	36	86	98
Balance, end of period	(1,878)	(2,121)	(1,878)	(2,121)
Brighthouse Financial, Inc
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	(2,512)	0	(2,512)	0
Deferred income tax benefit (expense)	878	0	878	0
Amounts reclassified from AOCI, net of income tax	(1,634)	0	(1,634)	0
Brighthouse Financial, Inc | Unrealized Investment Gains (Losses), Net of Related Offsets
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	(2,286)	0	(2,286)	0
Deferred income tax benefit (expense)	800	0	800	0
Amounts reclassified from AOCI, net of income tax	(1,486)	0	(1,486)	0
Brighthouse Financial, Inc | Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	(305)	0	(305)	0
Deferred income tax benefit (expense)	107	0	107	0
Amounts reclassified from AOCI, net of income tax	(198)	0	(198)	0
Brighthouse Financial, Inc | Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	51	0	51	0
Deferred income tax benefit (expense)	(19)	0	(19)	0
Amounts reclassified from AOCI, net of income tax	32	0	32	0
Brighthouse Financial, Inc | Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI	28	0	28	0
Deferred income tax benefit (expense)	(10)	0	(10)	0
Amounts reclassified from AOCI, net of income tax	$ 18	$ 0	$ 18	$ 0