Condensed Financial Information (Parent Company) (Condensed Statements of Operations) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Net Investment Income									$ 17,363	$ 16,790	$ 16,205
Other revenues									1,341	1,685	1,927
Net investment gains (losses)									(308)	317	609
Net derivative gains (losses)									(590)	(690)	629
Total revenues	$ 15,840	$ 16,171	$ 15,333	$ 14,964	$ 12,387	$ 15,806	$ 16,349	$ 16,245	62,308	60,787	61,343
Expenses
Goodwill impairment									0	260	0
Other expenses									13,621	13,749	14,777
Total expenses	14,879	15,686	14,315	13,892	14,058	14,717	13,979	13,752	58,772	56,506	55,692
Income (loss) from before provision for income tax									3,536	4,281	5,651
Provision for income tax expense (benefit)									(1,470)	693	1,590
Net income (loss)	2,317	(91)	911	873	(2,343)	542	321	2,330	4,010	850	5,373
Less: Preferred stock dividends	45	6	46	6	45	6	46	6	103	103	116
Preferred stock repurchase premium									0	0	42
Net Income (Loss) Available to Common Stockholders, Basic	$ 2,272	$ (97)	$ 865	$ 867	$ (2,388)	$ 536	$ 275	$ 2,324	3,907	747	5,215
Comprehensive income (loss)									7,391	1,449	(574)
Parent Company
Condensed Income Statements, Captions [Line Items]
Equity in earnings of subsidiaries									7,162	1,833	6,048
Net Investment Income									101	129	170
Other revenues									59	151	124
Net investment gains (losses)									(1,142)	86	12
Net derivative gains (losses)									(186)	(68)	(7)
Total revenues									5,994	2,131	6,347
Expenses
Interest expense									1,108	1,152	1,171
Goodwill impairment									0	147	0
Other expenses									657	388	180
Total expenses									2,059	1,689	1,351
Income (loss) from before provision for income tax									3,935	442	4,996
Provision for income tax expense (benefit)									(75)	(408)	(377)
Net income (loss)									4,010	850	5,373
Less: Preferred stock dividends									103	103	116
Preferred stock repurchase premium									0	0	42
Net Income (Loss) Available to Common Stockholders, Basic									3,907	747	5,215
Comprehensive income (loss)									7,391	1,449	(574)
Brighthouse Financial, Inc [Member]
Condensed Income Statements, Captions [Line Items]
Net investment gains (losses)									(1,016)
Expenses
Goodwill impairment										260
Brighthouse Financial, Inc [Member] | Parent Company
Expenses
Termination of financing arrangements									$ 294	$ 2	$ 0