Goodwill (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Goodwill [Line Items]
Acquisitions	$ 1,000,000	$ 39,000,000	$ 6,959,000,000
Goodwill	9,953,000,000	11,935,000,000	11,781,000,000	5,047,000,000
Impairments	(1,868,000,000)	0	0
MetLife Bank [Member]
Goodwill [Line Items]
Impairments		(65,000,000)
Parent Company [Member]
Goodwill [Line Items]
Impairments	(1,384,000,000)	0	0
Alico Transaction [Member]
Goodwill [Line Items]
Acquisitions		39,000,000
Japan [Member]
Goodwill [Line Items]
Goodwill	5,200,000,000	5,400,000,000
Retail [Member]
Goodwill [Line Items]
Acquisitions	0	0	0
Goodwill	1,433,000,000	3,125,000,000	3,125,000,000	3,125,000,000
Impairments	(1,692,000,000)	0
Goodwill impairment testing attributed to reportable segments		210,000,000
Group, Voluntary & Worksite Benefits [Member]
Goodwill [Line Items]
Acquisitions	0	0	0
Goodwill	138,000,000	138,000,000	138,000,000	138,000,000
Impairments	0	0
Goodwill impairment testing attributed to reportable segments		9,000,000
Corporate Benefit Funding [Member]
Goodwill [Line Items]
Acquisitions	0	0	0
Goodwill	900,000,000	900,000,000	900,000,000	900,000,000
Impairments	0	0
Goodwill impairment testing attributed to reportable segments		186,000,000
Retail Segment, Life & Other Reporting Unit [Member]
Goodwill [Line Items]
Goodwill impairment testing attributed to reporting unit		34,000,000
Retail Segment, Annuities Reporting Unit [Member]
Goodwill [Line Items]
Impairments	(1,900,000,000)
Goodwill impairment testing attributed to reporting unit		176,000,000
Goodwill impairment, net of income tax	$ (1,600,000,000)