Commitments (Details Textual) (USD $)	Feb. 08, 2013
Letters Of Credit Outstanding Amount Per Lot	$ 3,000,000
Letters of Credit Outstanding, Amount	$ 9,000,000

The amount of the contingent obligation under letters of credit outstanding per lot of crude barite as of the reporting date.

No definition available.

Name:	mbmi_LettersOfCreditOutstandingAmountPerLot
Namespace Prefix:	mbmi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant