Consolidated Statements Of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Statements of Comprehensive Income [Abstract]
Net income (loss) attributable to MetLife, Inc.	$ 1,324		$ 6,423		$ 2,667
Net income (loss) attributable to noncontrolling interests	29	[1]	5	[1]	(2)	[1]
Net income (loss)	1,353	[1]	6,428	[1]	2,665	[1]
Other comprehensive income (loss):
Unrealized investment gains (losses), net of related offsets	9,394		6,867		6,744
Unrealized gains (losses) on derivatives	(239)		1,573		17
Foreign currency translation adjustments	(139)		9		(580)
Defined benefit plans adjustment	(842)		(760)		165
Other comprehensive income (loss), before income tax	8,174		7,689		6,346
Income tax (expense) benefit related to items of other comprehensive income (loss)	(2,851)		(2,789)		(2,199)
Other comprehensive income (loss), net of income tax	5,323		4,900		4,147
Comprehensive income (loss)	6,676		11,328		6,812
Less: Comprehensive income (loss) attributable to noncontrolling interest, net of income tax	38		(33)		3
Comprehensive income (loss) attributable to MetLife, Inc., excluding cumulative effect of change in accounting principle	6,638		11,361		6,809
Cumulative effect of change in accounting principle, net of income tax	0		0		52
Comprehensive income (loss) attributable to MetLife, Inc.	$ 6,638		$ 11,361		$ 6,861

[1] Net income (loss) attributable to noncontrolling interests and net income (loss) exclude gains (losses) of redeemable noncontrolling interests in partially-owned consolidated subsidiaries of $9 million, $(13) million and $(2) million for the years ended December 31, 2012, 2011 and 2010, respectively.