Consolidated Statements of Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock at Cost	Accumulated Other Comprehensive Income (Loss)	Total MetLife, Inc.'s Stockholders' Equity	Noncontrolling Interests	Previously Reported	Previously Reported Preferred Stock	Previously Reported Common Stock	Previously Reported Additional Paid-in Capital	Previously Reported Retained Earnings	Previously Reported Treasury Stock at Cost	Previously Reported Accumulated Other Comprehensive Income (Loss)	Previously Reported Total MetLife, Inc.'s Stockholders' Equity	Previously Reported Noncontrolling Interests
Beginning Balance at Dec. 31, 2015	$ 68,568	$ 0	$ 12	$ 30,749	$ 35,672	$ (3,102)	$ 4,767	$ 68,098	$ 470
Preferred stock issuance	0
Treasury stock acquired in connection with share repurchases	(372)					(372)		(372)
Stock-based compensation	195			195				195
Dividends on preferred stock	(103)				(103)			(103)
Dividends on common stock	(1,736)				(1,736)			(1,736)
Change in equity of noncontrolling interests	(391)							0	(391)
Net income (loss)	854				850			850	4
Other comprehensive income (loss), net of income tax	687						599	599	88
Ending Balance at Dec. 31, 2016	67,702	0	12	30,944	34,683	(3,474)	5,366	67,531	171
Preferred stock issuance	0
Treasury stock acquired in connection with share repurchases	(2,927)					(2,927)		(2,927)
Stock-based compensation	167			167				167
Dividends on preferred stock	(103)				(103)			(103)
Dividends on common stock	(1,717)				(1,717)			(1,717)
Stockholders' Equity Note, Spinoff Transaction	(11,666)				(10,346)		(1,320)	(11,666)
Change in equity of noncontrolling interests	9							0	9
Net income (loss)	4,020				4,010			4,010	10
Other comprehensive income (loss), net of income tax	3,385						3,381	3,381	4
Ending Balance at Dec. 31, 2017	58,870									$ 58,870	$ 0	$ 12	$ 31,111	$ 26,527	$ (6,401)	$ 7,427	$ 58,676	$ 194
Cumulative effects of changes in accounting principles, net of income tax	7				(905)		912	7
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance	58,877	0	12	31,111	25,622	(6,401)	8,339	58,683	194
Preferred stock issuance	1,274			1,274				1,274
Treasury stock acquired in connection with share repurchases	(3,992)					(3,992)		(3,992)
Stock-based compensation	89			89				89
Dividends on preferred stock	(141)				(141)			(141)
Dividends on common stock	(1,678)				(1,678)			(1,678)
Change in equity of noncontrolling interests	16							0	16
Net income (loss)	5,128				5,123			5,123	5
Other comprehensive income (loss), net of income tax	(6,615)						(6,617)	(6,617)	2
Ending Balance at Dec. 31, 2018	$ 52,958	$ 0	$ 12	$ 32,474	$ 28,926	$ (10,393)	$ 1,722	$ 52,741	$ 217