Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Premiums									$ 882	$ 900	$ 863
Universal life and investment-type product policy fees									3,580	3,835	3,898
Net investment income									3,579	3,338	3,078
Other revenues									389	397	651
Net investment gains (losses)									112	(207)	(28)
Net derivative gains (losses)									(1,988)	702	(1,620)
Total revenues	$ 306	$ 3,187	$ 2,370	$ 691	$ 4,026	$ 1,422	$ 1,702	$ 1,815	6,554	8,965	6,842
Expenses
Policyholder benefits and claims									3,670	3,272	3,636
Interest credited to policyholder account balances									1,063	1,079	1,111
Amortization of DAC and VOBA									382	1,050	227
Other expenses									2,491	2,575	2,483
Total expenses	1,678	2,383	1,901	1,644	2,239	1,790	2,019	1,928	7,606	7,976	7,457
Income (loss) before provision for income tax									(1,052)	989	(615)
Provision for income tax expense (benefit)									(317)	119	(237)
Net income (loss)	(1,069)	685	384	(735)	1,442	(269)	(238)	(65)	(735)	870	(378)
Less: Net income (loss) attributable to noncontrolling interests	1	2	0	2	0	2	1	2	5	5	0
Net income (loss) attributable to Brighthouse Financial, Inc.	(1,070)	683	384	(737)	1,442	(271)	(239)	(67)	(740)	865	(378)
Less: Preferred stock dividends	7	7	7	0	0	0	0	0	21	0	0
Net income (loss) available to Brighthouse Financial, Inc.’s common shareholders	$ (1,077)	$ 676	$ 377	$ (737)	$ 1,442	$ (271)	$ (239)	$ (67)	$ (761)	$ 865	$ (378)
Earnings per common share
Basic	$ (10.02)	$ 6.09	$ 3.28	$ (6.31)	$ 12.18	$ (2.26)	$ (2.01)	$ (0.56)	$ (6.76)	$ 7.24	$ (3.16)
Diluted	$ (10.02)	$ 6.06	$ 3.27	$ (6.31)	$ 12.14	$ (2.26)	$ (2.01)	$ (0.56)	$ (6.76)	$ 7.21	$ (3.16)