Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 6,575	$ 5,418	$ 5,909
Other comprehensive income (loss):
Unrealized investment gains (losses), net of related offsets	(8,171)	5,198	14,591
Unrealized gains (losses) on derivatives	137	(286)	60
Foreign currency translation adjustments	(1,306)	1,169	(42)
Defined benefit plans adjustment	328	181	30
Other comprehensive income (loss), before income tax	(9,012)	6,262	14,639
Income tax (expense) benefit related to items of other comprehensive income (loss)	1,862	(1,237)	(3,324)
Other comprehensive income (loss), net of income tax	(7,150)	5,025	11,315
Comprehensive income (loss)	(575)	10,443	17,224
Less: Comprehensive income (loss) attributable to noncontrolling interest, net of income tax	24	16	16
Comprehensive income (loss) attributable to MetLife, Inc.	$ (599)	$ 10,427	$ 17,208