Equity (Statutory Equity & Income and Dividend Restrictions - Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2018
Parent Company
Statutory Accounting Practices [Line Items]
Paid	$ 0	$ 261
Parent Company | Scenario, Forecast
Statutory Accounting Practices [Line Items]
Permitted w/o approval				$ 84
Brighthouse Life Insurance Company [Member]
Statutory Accounting Practices [Line Items]
RBC Adjusted Ratios	in excess of 400%	in excess of 400%
Statutory Accounting Practices, Statutory Net Income Amount	$ (425)	$ 1,186	$ (1,022)
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	5,594	4,374
Brighthouse Reinsurance Company of Delaware
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Prescribed Practice, Amount	8,300
Paid	535
Statutory Accounting Practices, Statutory Net Income Amount	(1,600)
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	$ 972	$ 2,600
Brighthouse Life Insurance Co of NY [Member]
Statutory Accounting Practices [Line Items]
RBC Adjusted Ratios	in excess of 400%	in excess of 400%
Paid	$ 0	$ 0
Statutory Accounting Practices, Statutory Net Income Amount	22	(87)	17
Statutory Accounting Practices, Statutory Capital and Surplus, Balance	$ 294	196
Brighthouse Life Insurance Co of NY [Member] | Scenario, Forecast
Statutory Accounting Practices [Line Items]
Permitted w/o approval				$ 21
Metlife Reinsurance Company of Vermont Cell [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Prescribed Practice, Amount		3,000
MetLife Reinsurance Company of Delaware [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Prescribed Practice, Amount		260
Domestic Captive Life Reinsurance Subsidiaries [Member]
Statutory Accounting Practices [Line Items]
Statutory Accounting Practices, Statutory Net Income Amount		$ (363)	$ (372)