Earnings Per Common Share (Earnings Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Weighted Average Shares:
Weighted average common stock outstanding - basic	682.3	723.2
Incremental common shares from assumed exercise or issuance of stock-based awards	4.7	5.2
Weighted average common stock outstanding - diluted	687.0	728.4
Net Income (Loss):
Net income (loss)	$ 950	$ 875
Less: Net income (loss) attributable to noncontrolling interests	5	8
Less: Preferred stock dividends	66	67
Net income (loss) available to MetLife, Inc.’s common shareholders	$ 879	$ 800
Basic	$ 1.29	$ 1.11
Diluted	$ 1.28	$ 1.10