Equity (Statutory Net Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Metropolitan Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	$ 3,656	$ 1,982	$ 3,444
Statutory capital and surplus	11,098	10,384
American Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	2,086	3,077	341
Statutory capital and surplus	4,921	6,548
Brighthouse Life Insurance Company [Member]
Statutory Accounting Practices [Line Items]
Statutory net income (loss)			1,186
Metropolitan Property and Casualty Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	345	197	171
Statutory capital and surplus	2,322	2,266
Metropolitan Tower Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	76	164	8
Statutory capital and surplus	1,549	1,751
New England Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)			109
Other
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	16	11	(70)
Statutory capital and surplus	$ 106	$ 100
General American Life Insurance Company [Member]
Statutory Accounting Practices [Line Items]
Statutory net income (loss)			(2)
Brighthouse Financial, Inc
Statutory Accounting Practices [Line Items]
Statutory net income (loss)			$ (87)