Contingencies, Commitments and Guarantees (Contingencies - Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2014 Claims	Mar. 31, 2013 Claims	Dec. 31, 2013 Claims
Minimum [Member]
Loss Contingencies
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
Maximum [Member]
Loss Contingencies
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	460,000,000
Superfund Site Settlement Agreements [Member]
Loss Contingencies
Number of regulatory matters and other claims	2
Damages Sought	less than $1 million and an additional amount
Maximum estimate of aggregate costs to resolve matter	1,000,000
Maximum estimate of costs for environmental testing	100,000
Total Asset Recovery Services, LLC Florida v. MetLife, Inc et Al [Member]
Loss Contingencies
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
C-Mart, Inc. V. Metropolitan Life Insurance Company, Et Al [Member]
Loss Contingencies
Damages Sought	$500 for each violation
Number of plaintiffs	36,000
Derivative Actions And Demands [Member]
Loss Contingencies
Number of plaintiffs	4
Asbestos Related Claims [Member]
Loss Contingencies
Asbestos-Related Claims	1,366	1,435	5,898
New York Licensing Inquiry [Member] | Department of Financial Services [Member]
Loss Contingencies
Litigation Settlement, Amount	50,000,000
New York Licensing Inquiry [Member] | New York County, District Attorney [Member]
Loss Contingencies
Litigation Settlement, Amount	$ 10,000,000