Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 5,909	$ 5,128	$ 4,020
Other comprehensive income (loss):
Unrealized investment gains (losses), net of related offsets	14,591	(8,719)	4,623
Unrealized gains (losses) on derivatives	60	674	(1,165)
Foreign currency translation adjustments	(42)	(587)	767
Defined benefit plans adjustment	30	263	144
Other comprehensive income (loss), before income tax	14,639	(8,369)	4,369
Income tax (expense) benefit related to items of other comprehensive income (loss)	(3,324)	1,754	(984)
Other comprehensive income (loss), net of income tax	11,315	(6,615)	3,385
Comprehensive income (loss)	17,224	(1,487)	7,405
Less: Comprehensive income (loss) attributable to noncontrolling interest, net of income tax	16	7	14
Comprehensive income (loss) attributable to MetLife, Inc.	$ 17,208	$ (1,494)	$ 7,391