Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Plans - Subsequent to the IPO - 2013 Omnibus Equity Incentive Plan - Award Limitations - Additional Information (Detail)

v2.4.1.9
Stock-Based Compensation Plans - Subsequent to the IPO - 2013 Omnibus Equity Incentive Plan - Award Limitations - Additional Information (Detail) (USD $)
In Millions, except Share data, unless otherwise specified
 1 Months Ended 12 Months Ended 1 Months Ended
Dec. 31, 2014
Nov. 30, 2014
Aug. 31, 2014
May 31, 2014
Feb. 28, 2014
Dec. 31, 2014
Nov. 30, 2013
Nov. 05, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share-based awards granted during the period 216,411us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod 14,222us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod 18,820us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod 61,655us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod 38,088us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod 349,196us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod    
IPO [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Common stock sold and issued under IPO, price per share             12us-gaap_SharePrice
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember 		$ 12.00us-gaap_SharePrice
/ us-gaap_SubsidiarySaleOfStockAxis
= us-gaap_IPOMember
2013 Omnibus Equity Incentive Plan [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of active equity plans           1mmi_NumberOfActiveEquityPlans
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember 		   
Common stock shares reserved for issuance of awards 5,500,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember 		        5,500,000us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember 		   
Common stock shares available for grant 2,193,063us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember 		        2,193,063us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember 		   
Common stock available for future issuance authorized annual percentage increase           3.00%mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfAvailableShareIncrease
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember 		   
Increase of common stock share reserve approved           1,100,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableShareIncrease
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember 		   
Description of awards granted under the 2013 Plan           In November 2013, MMI issued the following equity awards under the 2013 Plan (i) DSUs for an aggregate of 2,192,413 shares granted as replacement awards related to the prior SARs program to the MMREIS managing directors, (ii) DSUs for 83,334 shares to be granted to the Company's Co-chairman of the board of directors (Mr. Millichap). The DSU's are fully vested and will be issued ratably over 5 years. In addition, 30,000 shares, in the form of RSAs, was granted to the Company's non-employee directors. The shares vest ratably over 3 years. All the above awards were granted based on the IPO price of $12.00.    
Deferred stock units [Member] | 2013 Omnibus Equity Incentive Plan [Member] | MMREIS Managing Directors [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Fully vested deferred stock units           2,192,413mmi_FullyVestedDeferredStockUnits
/ us-gaap_AwardTypeAxis
= mmi_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember
/ us-gaap_TitleOfIndividualAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesManagingDirectorsMember 		2,192,413mmi_FullyVestedDeferredStockUnits
/ us-gaap_AwardTypeAxis
= mmi_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember
/ us-gaap_TitleOfIndividualAxis
= mmi_MarcusAndMillichapRealEstateInvestmentServicesManagingDirectorsMember 		 
Deferred stock units [Member] | 2013 Omnibus Equity Incentive Plan [Member] | Millichap [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Fully vested deferred stock units             83,334mmi_FullyVestedDeferredStockUnits
/ us-gaap_AwardTypeAxis
= mmi_DeferredStockUnitsMember
/ us-gaap_PlanNameAxis
= mmi_TwoThousandAndThirteenOmnibusEquityAwardPlanMember
/ us-gaap_TitleOfIndividualAxis
= us-gaap_BoardOfDirectorsChairmanMember 		 
Restricted Stock [Member] | Non-employee directors [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share-based awards granted during the period       22,884us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_TitleOfIndividualAxis
= mmi_NonEmployeeDirectorMember 		  22,884us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_TitleOfIndividualAxis
= mmi_NonEmployeeDirectorMember 		30,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_RestrictedStockMember
/ us-gaap_TitleOfIndividualAxis
= mmi_NonEmployeeDirectorMember 		 
Options & SARs [Member] | Minimum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share limitations to awards granted under the 2013 Plan 500,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_OptionsAndStockAppreciationRightsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		        500,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_OptionsAndStockAppreciationRightsMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		   
Options & SARs [Member] | Maximum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share limitations to awards granted under the 2013 Plan 1,000,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_OptionsAndStockAppreciationRightsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		        1,000,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_OptionsAndStockAppreciationRightsMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		   
Restricted Stock and RSUs [Member] | Minimum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share limitations to awards granted under the 2013 Plan 500,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_RestrictedStockAndRsuMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		        500,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_RestrictedStockAndRsuMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		   
Restricted Stock and RSUs [Member] | Maximum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share limitations to awards granted under the 2013 Plan 1,000,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_RestrictedStockAndRsuMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		        1,000,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= mmi_RestrictedStockAndRsuMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		   
Performance Shares [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Number of award limitation, performance units or performance shares           1mmi_NumberOfAwardLimitationPerformanceUnitsOrPerformanceShares
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember 		   
Performance Shares [Member] | Minimum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share limitations to awards granted under the 2013 Plan 500,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		        500,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		   
Grant date fair value limitations to awards granted under the 2013 Plan           2mmi_PerformanceUnitsAndPerformanceSharesGrantsInPeriodFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_RangeAxis
= us-gaap_MinimumMember 		   
Performance Shares [Member] | Maximum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Share limitations to awards granted under the 2013 Plan 1,000,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		        1,000,000mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesLimitedInPeriod
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember 		   
Grant date fair value limitations to awards granted under the 2013 Plan           5mmi_PerformanceUnitsAndPerformanceSharesGrantsInPeriodFairValue
/ us-gaap_AwardTypeAxis
= us-gaap_PerformanceSharesMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember