Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v2.4.1.9
Income Taxes - Additional Information (Detail) (USD $)
 0 Months Ended 12 Months Ended
Oct. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Income Taxes [Line Items]        
State and Canadian net operating losses (NOLs)   3,500,000us-gaap_OperatingLossCarryforwards    
State and Canadian net operating losses (NOLs), expiration year   2019    
Valuation allowance, deferred tax assets   728,000us-gaap_DeferredTaxAssetsValuationAllowance 286,000us-gaap_DeferredTaxAssetsValuationAllowance  
Change in valuation allowance, deferred tax assets   442,000us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount    
Tax computed at federal rate, percentage   35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Reduction to income tax payable   (6,900,000)us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable    
Tax benefit related to settlement of DSUs, RSAs and IPO transaction costs   5,200,000mmi_TaxBenefitRelatedToSettlementOfDeferredStockUnitsRestrictedStockAwardsDeductibleIpoTransactionCosts    
Uncertain tax positions   0us-gaap_LiabilityForUncertainTaxPositionsCurrent 0us-gaap_LiabilityForUncertainTaxPositionsCurrent  
Income Tax Examination, Description   The Company is not currently under income tax examination by any taxing authorities.    
Undistributed earnings of foreign subsidiary   0us-gaap_UndistributedEarningsOfForeignSubsidiaries    
Tax sharing agreement termination date   Oct. 31, 2013    
Deferred tax assets, net transferred from parent prior to IPO 26,600,000us-gaap_DeferredTaxAssetsLiabilitiesNet   26,572,000us-gaap_DeferredTaxAssetsLiabilitiesNet  
Minimum [Member]        
Income Taxes [Line Items]        
Open tax years subject to tax examinations   2009    
Maximum [Member]        
Income Taxes [Line Items]        
Open tax years subject to tax examinations   2014    
Tax-sharing agreement [Member]        
Income Taxes [Line Items]        
Effective income tax rate, pre-IPO 43.50%us-gaap_EffectiveIncomeTaxRateContinuingOperations
/ us-gaap_TypeOfArrangementAxis
= mmi_TaxSharingAgreementMember 		  43.50%us-gaap_EffectiveIncomeTaxRateContinuingOperations
/ us-gaap_TypeOfArrangementAxis
= mmi_TaxSharingAgreementMember 		43.50%us-gaap_EffectiveIncomeTaxRateContinuingOperations
/ us-gaap_TypeOfArrangementAxis
= mmi_TaxSharingAgreementMember
Tax sharing agreement termination date   Oct. 31, 2013