Equity (Statutory Net Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Metropolitan Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	$ 3,513	$ 3,392	$ 3,859
Statutory capital and surplus	11,804	11,312
American Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	48	980	1,386
Statutory capital and surplus	5,584	4,419
Metropolitan Property and Casualty Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)		336	245
Statutory capital and surplus		2,249
Metropolitan Tower Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	185	(237)	(13)
Statutory capital and surplus	1,638	1,387
Other
Statutory Accounting Practices [Line Items]
Statutory net income (loss)	76	84	$ 12
Statutory capital and surplus	$ 193	$ 186