Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Additional Information (Detail)

v2.4.1.9
Stockholders' Equity - Additional Information (Detail) (USD $)
0 Months Ended 10 Months Ended 12 Months Ended
Nov. 05, 2013
Oct. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Mar. 31, 2013
Nov. 30, 2013
Stockholders Equity [Line Items]              
Common stock, shares issued     36,918,442us-gaap_CommonStockSharesIssued 36,600,897us-gaap_CommonStockSharesIssued      
Common stock, shares outstanding     36,918,442us-gaap_CommonStockSharesOutstanding 36,600,897us-gaap_CommonStockSharesOutstanding      
Common stock share, par value   $ 1.00us-gaap_CommonStockParOrStatedValuePerShare $ 0.0001us-gaap_CommonStockParOrStatedValuePerShare $ 0.0001us-gaap_CommonStockParOrStatedValuePerShare      
Common stock dividends declared and paid     $ 0us-gaap_DividendsCommonStock        
Preferred stock, shares authorized     25,000,000us-gaap_PreferredStockSharesAuthorized 25,000,000us-gaap_PreferredStockSharesAuthorized      
Preferred stock, par value     $ 0.0001us-gaap_PreferredStockParOrStatedValuePerShare $ 0.0001us-gaap_PreferredStockParOrStatedValuePerShare      
Preferred stock, shares issued     0us-gaap_PreferredStockSharesIssued 0us-gaap_PreferredStockSharesIssued      
Preferred stock, shares outstanding     0us-gaap_PreferredStockSharesOutstanding 0us-gaap_PreferredStockSharesOutstanding      
Preferred stock, voting rights   The pre-IPO Series A Preferred stockholders did not have voting rights.          
Prior to completion of IPO date     Oct. 30, 2013        
Proceeds from IPO 42,300,000mmi_ProceedsFromIssuanceInitialPublicOfferingNet            
IPO related expenses 4,300,000mmi_OtherOfferingCosts            
Preferred stock dividends declared and paid   37,681,000us-gaap_DividendsPreferredStock   37,681,000us-gaap_DividendsPreferredStock 30,756,000us-gaap_DividendsPreferredStock    
Stock appreciations rights liability, amount     20,542,000mmi_StockAppreciationRightsLiability 19,970,000mmi_StockAppreciationRightsLiability   20,000,000mmi_StockAppreciationRightsLiability  
Notes payable to former stockholders     11,504,000us-gaap_OtherNotesPayable        
Interest expense related to notes payable to former stockholders       318,000mmi_InterestExpenseRelatedToNotesPayablePriorToIpo      
Deferred tax assets, net transferred from parent prior to IPO   26,600,000us-gaap_DeferredTaxAssetsLiabilitiesNet   26,572,000us-gaap_DeferredTaxAssetsLiabilitiesNet      
Deferred tax assets, net transferred from parent prior to IPO, effective tax rate used for calculation       40.00%mmi_EffectiveTaxRateDeferredTaxAssetsNet      
IPO [Member]              
Stockholders Equity [Line Items]              
Common stock issued 6,900,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
           
IPO completion date     November 5, 2013        
Common stock sold and issued under IPO, price per share $ 12.00us-gaap_SharePrice
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
          $ 12us-gaap_SharePrice
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
IPO MMI [Member]              
Stockholders Equity [Line Items]              
Common stock issued 4,173,413us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_SubsidiarySaleOfStockAxis
= mmi_IpoMmiMember
           
IPO Underwriters [Member]              
Stockholders Equity [Line Items]              
Common stock issued 900,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_SubsidiarySaleOfStockAxis
= mmi_IpoUnderwritersMember
           
Underwriting discounts and commissions 3,500,000us-gaap_ExpenseRelatedToDistributionOrServicingAndUnderwritingFees
/ us-gaap_SubsidiarySaleOfStockAxis
= mmi_IpoUnderwritersMember
           
IPO Selling Stockholder [Member]              
Stockholders Equity [Line Items]              
Common stock issued 2,726,587us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_SubsidiarySaleOfStockAxis
= mmi_IpoSellingStockholderMember
           
MMREIS [Member]              
Stockholders Equity [Line Items]              
Common stock, shares issued   234,489us-gaap_CommonStockSharesIssued
/ dei_LegalEntityAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesMember
    234,489us-gaap_CommonStockSharesIssued
/ dei_LegalEntityAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesMember
   
Common stock, shares outstanding   234,489us-gaap_CommonStockSharesOutstanding
/ dei_LegalEntityAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesMember
    234,489us-gaap_CommonStockSharesOutstanding
/ dei_LegalEntityAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesMember
   
Common stock dividends declared and paid       0us-gaap_DividendsCommonStock
/ dei_LegalEntityAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesMember
0us-gaap_DividendsCommonStock
/ dei_LegalEntityAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesMember
   
Exchange of Stock for Stock [Member] | MMC [Member]              
Stockholders Equity [Line Items]              
Common stock share, par value   $ 0.0001us-gaap_CommonStockParOrStatedValuePerShare
/ us-gaap_FreshStartAdjustmentsTypeOfFreshStartAdjustmentAxis
= us-gaap_ExchangeOfStockForStockMember
/ dei_LegalEntityAxis
= mmi_MarcusAndMillichapCompanyMember
         
Notes Payable APIC [Member]              
Stockholders Equity [Line Items]              
Notes payable to former stockholders       $ 12,200,000us-gaap_OtherNotesPayable
/ us-gaap_ShortTermDebtTypeAxis
= mmi_NotesPayableApicMember
     
Series A redeemable preferred stock [Member]              
Stockholders Equity [Line Items]              
Preferred stock, par value   $ 10.00us-gaap_PreferredStockParOrStatedValuePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
         
Preferred stock, shares issued         1,000us-gaap_PreferredStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
   
Preferred stock, shares outstanding         1,000us-gaap_PreferredStockSharesOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
   
Preferred stock liquidation preference per share   $ 10us-gaap_PreferredStockLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
    $ 10us-gaap_PreferredStockLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
   
Preferred stock, redemption value per share   $ 10us-gaap_PreferredStockRedemptionPricePerShare
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
         
Exchange of common stock   1,000us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
    1,000us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
   
Preferred stock, dividend per share   $ 10mmi_SeriesaPreferredStockDividendReturn
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
    $ 10mmi_SeriesaPreferredStockDividendReturn
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
   
MMREIS Common Stock [Member]              
Stockholders Equity [Line Items]              
Exchange of common stock   234,489us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesCommonStockMember
    234,489us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesCommonStockMember
   
Marcus And Millichap Common Stock [Member]              
Stockholders Equity [Line Items]              
Exchange of common stock   32,357,901us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= mmi_MarcusAndMillichapCommonStockMember
         
MMREIS Managing Directors [Member] | MMREIS Common Stock [Member]              
Stockholders Equity [Line Items]              
Exchange of common stock   28,749us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesCommonStockMember
/ us-gaap_TitleOfIndividualAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesManagingDirectorsMember
         
Restricted Stock [Member] | Non-employee directors [Member]              
Stockholders Equity [Line Items]              
Common stock issued     42,882us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_TitleOfIndividualAxis
= mmi_NonEmployeeDirectorMember
30,000us-gaap_StockIssuedDuringPeriodSharesNewIssues
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_TitleOfIndividualAxis
= mmi_NonEmployeeDirectorMember