Equity (Net Unrealized Investment Gains Losses) (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Components of net unrealized investment gains (losses) included in accumulated other comprehensive income
Fixed maturity securities AFS	$ (21,083)	$ (29,262)
Derivatives	2,231	1,976
Other	543	549
Subtotal	(18,309)	(26,737)
Policyholder liabilities	79	120
Deferred income tax benefit (expense)	3,624	5,545
Net unrealized investment gains (losses)	(14,606)	(21,072)
Net unrealized investment gains (losses) attributable to noncontrolling interests	0	(17)
Net unrealized investment gains (losses) attributable to MetLife, Inc.	$ (14,606)	$ (21,089)