Contingencies, Commitments and Guarantees (Contingencies - Narrative) (Details) (USD $)			9 Months Ended				3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013 Minimum [Member]	Sep. 30, 2013 Maximum [Member]	Sep. 30, 2013 Superfund Site Settlement Agreements [Member] Claims	Sep. 30, 2013 Merrill Haviland, et Al v. Metropolitan Life Insurance Company [Member] Plaintiffs	Sep. 30, 2013 Total Asset Recovery Services, LLC Florida v. MetLife, Inc et Al [Member] Contracts	Sep. 30, 2013 C-Mart, Inc. V. Metropolitan Life Insurance Company, Et Al [Member]	Mar. 31, 2012 Unclaimed Property [Member]	Sep. 30, 2013 Derivative Actions And Demands [Member] Plaintiffs	Mar. 31, 2013 MetLife Bank Mortgage Regulatory and Law Enforcement Authorities' Inquiries [Member]	Sep. 30, 2013 MetLife Bank Mortgage Regulatory and Law Enforcement Authorities' Inquiries [Member]	Sep. 30, 2013 Asbestos Related Claims [Member] Claims	Sep. 30, 2012 Asbestos Related Claims [Member] Claims	Dec. 31, 2012 Asbestos Related Claims [Member] Claims
Loss Contingencies
After tax charge for the multistate examination payment and the expected acceleration of benefit payments to policyholders under settlements							$ 52,000,000
Number of regulatory matters and other claims			2
Damages Sought			less than $1 million and an additional amount			$500 for each violation
Damages Sought					767,000,000
Assumed average face amount of life insurance policies in lawsuit					120,000
Number of life insurance contracts named in legal action					9,022
Number of plaintiffs				45				5
Loss Contingency, Range of Possible Loss, Maximum										3,200,000
Maximum estimate of aggregate costs to resolve matter			1,000,000
Maximum estimate of costs for environmental testing			100,000
The approximate amount of the aggregate range of reasonably possible losses in excess of amounts accrued for matters as to which an estimate can be made	0	445,000,000
Litigation Settlement, Amount									$ 46,000,000
Asbestos-Related Claims											4,256	3,909	5,303