Annual report pursuant to Section 13 and 15(d)

Property and Equipment - Additional Information (Detail)

v2.4.1.9
Property and Equipment - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Property, Plant and Equipment [Line Items]      
Depreciation and amortization expense on property and equipment $ 3,206,000us-gaap_DepreciationAndAmortization $ 3,043,000us-gaap_DepreciationAndAmortization $ 2,981,000us-gaap_DepreciationAndAmortization
Capital lease obligations 0us-gaap_CapitalLeaseObligations    
Furniture, fixtures, and equipment [Member]      
Property, Plant and Equipment [Line Items]      
Fully depreciated no longer in use furniture, fixtures and equipment write-off $ 7,700,000mmi_FullyDepreciatedNoLongerInUseFurnitureFixturesAndEquipmentWriteOff
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_FurnitureAndFixturesMember