Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information Credit Agreement (Detail)

v2.4.1.9
Commitments and Contingencies - Additional Information Credit Agreement (Detail) (USD $)
 0 Months Ended 12 Months Ended
Jan. 02, 2014
Dec. 31, 2014
Ratio
Dec. 31, 2013
Dec. 31, 2012
Line of Credit Facility [Line Items]        
Senior secured revolving credit facility maximum borrowing capacity   $ 60,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity    
Revolving credit facility maturity date   Jun. 01, 2017    
Bank fees and other expenses   224,000us-gaap_DeferredFinanceCostsGross    
Credit agreement, unused capacity, commitment fee percentage   0.10%us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage    
Commitment fee commencement date   Jul. 01, 2014    
Date the Company entered into a Credit Agreement   Jun. 18, 2014    
Credit agreement date   Jun. 01, 2014    
Interest expense   1,651,000us-gaap_InterestExpense 105,000us-gaap_InterestExpense 4,000us-gaap_InterestExpense
Credit agreement, amount outstanding   0us-gaap_LineOfCredit    
Standby letters of credit borrowing capacity   10,000,000mmi_StandbyLettersOfCreditSublimit    
Credit facility interest rate description   Credit Facility will bear interest, at the Company's option, at either the (i) Base Rate (defined as the highest of (a) the Bank's prime rate, (b) the Federal Funds Rate plus 1.5% and (c) one-month LIBOR plus 1.5%), or (ii) at a variable rate between 0.875% and 1.125% above LIBOR, based upon the total funded debt to EBITDA ratio.    
Base spread on variable rate 2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1      
LIBOR rate duration period   1 month    
Credit facility covenants   (i) an EBITDAR Coverage Ratio (as defined in the Credit Agreement) of not less than 1.251.0 as of each quarter end on a rolling 4-quarter basis and (ii) total funded debt to EBITDA not greater than 2.01.0    
Minimum EBITDAR coverage ratio   1.25mmi_MinimumEbitdarCoverageRatio    
Maximum Total Funded Debt to EBITDA ratio   2.0mmi_MaximumFundedDebtToEbitdaRatio    
Credit agreement, pledge percentage   100.00%mmi_CreditFacilityPledgePercentage    
Compliance description   As of December 31, 2014, the Company was in compliance with all financial and non-financial covenants.    
London Interbank Offered Rate (LIBOR) [Member]        
Line of Credit Facility [Line Items]        
Base spread on variable rate   1.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_VariableRateAxis
= us-gaap_LondonInterbankOfferedRateLIBORMember 		   
Credit Agreement [Member]        
Line of Credit Facility [Line Items]        
Interest expense   $ 76,000us-gaap_InterestExpense
/ us-gaap_CreditFacilityAxis
= mmi_CreditAgreementMember 		   
Federal Funds Rate [Member]        
Line of Credit Facility [Line Items]        
Base spread on variable rate   1.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= mmi_FederalFundsRateMember 		   
Minimum [Member] | Variable Rate [Member]        
Line of Credit Facility [Line Items]        
Base spread on variable rate   0.875%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= mmi_VariableRateMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		   
Maximum [Member] | Variable Rate [Member]        
Line of Credit Facility [Line Items]        
Base spread on variable rate   1.125%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_CreditFacilityAxis
= mmi_VariableRateMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember