Investments (Details 13) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Components of net unrealized investment gains (losses) included in accumulated other comprehensive loss
Fixed maturity securities that were temporarily impaired	$ 33,641	$ 21,096	$ 7,817
Fixed maturity securities with noncredit OTTI losses in accumulated other comprehensive income (loss)	(361)	(724)	(601)
Total fixed maturity securities	33,280	20,372	7,216
Equity securities	97	(167)	(3)
Derivatives	1,274	1,514	(59)
Other	(30)	72	42
Subtotal	34,621	21,791	7,196
Insurance liability loss recognition	(6,049)	(3,996)	(672)
DAC and VOBA related to noncredit OTTI losses recognized in accumulated other comprehensive income (loss)	19	47	38
DAC and VOBA	(2,485)	(1,800)	(1,003)
Policyholder dividend obligation	(3,828)	(2,919)	(876)
Subtotal	(12,343)	(8,668)	(2,513)
Deferred income tax benefit (expense) related to noncredit OTTI losses recognized in accumulated other comprehensive income (loss)	119	236	197
Deferred income tax benefit (expense)	(7,973)	(4,694)	(1,762)
Net unrealized investment gains (losses)	14,424	8,665	3,118
Net unrealized investment gains (losses) attributable to noncontrolling interests	(5)	9	4
Net unrealized investment gains (losses) attributable to MetLife, Inc.	$ 14,419	$ 8,674	$ 3,122	$ (1,338)