Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock at Cost	Accumulated Other Comprehensive Income (Loss)	Total MetLife, Inc.'s Stockholders' Equity	Total MetLife, Inc.'s Stockholders' Equity Cumulative Effect, Period of Adoption, Adjustment	Noncontrolling Interests
Beginning Balance at Dec. 31, 2019	$ 66,382	$ (121)	$ 0	$ 12	$ 32,680	$ 33,078	$ (121)	$ (12,678)	$ 13,052	$ 66,144	$ (121)	$ 238
Preferred stock issuance	972				972					972
Treasury stock acquired in connection with share repurchases	(500)							(500)		(500)
Stock-based compensation	59				59					59
Dividends on preferred stock	$ (32)					(32)				(32)
Dividend Per Share	$ 0.440
Dividends on common stock	$ (404)					(404)				(404)
Net income (loss)	4,401					4,398				4,398		3
Other comprehensive income (loss), net of income tax	(294)								(295)	(295)		1
Ending Balance at Mar. 31, 2020	70,463		0	12	33,711	36,919		(13,178)	12,757	70,221		242
Beginning Balance at Dec. 31, 2020	74,817		0	12	33,812	36,491		(13,829)	18,072	74,558		259
Preferred stock issuance	0
Treasury stock acquired in connection with share repurchases	(999)							(999)		(999)
Stock-based compensation	98				98					98
Dividends on preferred stock	$ (68)					(68)				(68)
Dividend Per Share	$ 0.460
Dividends on common stock	$ (408)					(408)				(408)
Change in equity of noncontrolling interests	9									0		9
Net income (loss)	363					358				358		5
Other comprehensive income (loss), net of income tax	(7,675)								(7,675)	(7,675)		0
Ending Balance at Mar. 31, 2021	$ 66,137		$ 0	$ 12	$ 33,910	$ 36,373		$ (14,828)	$ 10,397	$ 65,864		$ 273