Equity - Statutory Equity & Income Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Principal U.S. Insurance Subsidiaries, Excluding American Life
Statutory Accounting Practices [Line Items]
Combined RBC ratio of the principal U.S. insurance subsidiaries	in excess of 380%	in excess of 340%
Metropolitan Life Insurance Company
Statutory Accounting Practices [Line Items]
Statutory capital and surplus	$ 11,593	$ 10,869
Prescribed practice, amount	1,400	1,300
Statutory net income (loss)	3,407	2,737	$ 3,513
MetLife Reinsurance Company of Vermont
Statutory Accounting Practices [Line Items]
Prescribed practice, amount	2,000	2,000
MetLife's Domestic Captive Life Reinsurance Subsidiaries
Statutory Accounting Practices [Line Items]
Statutory capital and surplus	723	726
Statutory net income (loss)	$ 63	$ 44	$ 41
Japan
Statutory Accounting Practices [Line Items]
Adjusted capital	in excess of three times the 200% solvency margin ratio	in excess of three times the 200% solvency margin ratio
Other Foreign Operations, Excluding Japan
Statutory Accounting Practices [Line Items]
Statutory capital and surplus required	$ 3,100
Statutory capital and surplus	$ 7,400