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Stock-Based Compensation Plans - Employee Stock Purchase Plan - Additional Information (Detail) (USD $)
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3 Months Ended |
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Mar. 31, 2015
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Unrecognized stock-based compensation expense | $ 28,221,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized |
| Unrecognized stock-based compensation expenses recognition period | 3 years 11 months 12 days |
| Employee Stock Purchase Plan [Member] | |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| ESPP offering period description | The offering periods generally start on the first trading day on or after May 15 and November 15 of each year. The first offering period began on May 15, 2014. |
| Length of purchase intervals | 6 months |
| ESPP discount rate |
10.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Expected dividend yield |
0.00%us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Forfeiture rate |
0.00%mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardForfeitureRate / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Common stock reserved and available for issuance |
366,667us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Common stock shares available for issuance |
341,356us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Common stock available for future issuance authorized annual share increase |
366,667mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableShareIncrease / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Common stock available for future issuance authorized annual percentage increase |
1.00%mmi_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfAvailableShareIncrease / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Unrecognized stock-based compensation expense |
$ 31,000us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized / us-gaap_AwardTypeAxis = mmi_EmployeeStockPurchasePlanMember |
| Unrecognized stock-based compensation expenses recognition period | 1 month 13 days |
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- Definition
Employee Stock Purchase Plan Offering Period Description No definition available.
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- Definition
Annual share increase in share reserve allowed under the 2013 Plan. No definition available.
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- Definition
Share Based Compensation Arrangement By Share Based Payment Award Forfeiture Rate No definition available.
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- Definition
Represents the length of purchase intervals. No definition available.
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- Definition
Percentage of available share increase in share reserve allowed under the 2013 Equity and 2013 ESPP plans, calculated as a percentage of outstanding shares. No definition available.
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- Definition
Unrecognized cost of unvested share-based compensation awards. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Discount rate from fair value on purchase date that participants pay for shares. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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