Marcus & Millichap, Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Description of business, basis of presentation and recent accounting pronouncements (Policies)
Notes Tables
Notes Details

Description of Business and Basis of Presentation - Additional Information (Detail)

v3.8.0.1

Description of Business and Basis of Presentation - Additional Information (Detail)		3 Months Ended		9 Months Ended
	Jan. 01, 2017 USD ($)	Sep. 30, 2017 USD ($) Office	Sep. 30, 2016 Office	Sep. 30, 2017 USD ($) Office	Sep. 30, 2016 Office	Dec. 31, 2016 USD ($)
Class of Stock [Line Items]
Number of offices in the United States and Canada \| Office				79
Formation date				2013-06
Percentage of common stock distributed				80.00%
Commission's receivable settled period				10 days
Marketable securities, available for sale		$ 128,257,000		$ 128,257,000		$ 104,929,000
IPO MMI [Member]
Class of Stock [Line Items]
IPO completion date				Oct. 30, 2013
Accounting Standards Update 2016-13 [Member] \| Average AA Credit Rating [Member]
Class of Stock [Line Items]
Marketable securities, available for sale		128,300,000		$ 128,300,000
Impairment write-downs marketable securities, available for sale				0
Accounting Standards Update 2016-09 [Member]
Class of Stock [Line Items]
Cumulative effect adjustments, net of tax	$ 52,000
Accounting Standards Update 2016-02 [Member]
Class of Stock [Line Items]
Operating lease obligations		$ 83,200,000		$ 83,200,000
Geographic Concentration Risk [Member] \| Total revenues [Member]
Class of Stock [Line Items]
Concentration risk percentage		10.00%	10.00%	10.00%	10.00%
Number of offices \| Office		1	0	0	0
Customer Concentration Risk [Member] \| Total revenues [Member]
Class of Stock [Line Items]
Concentration risk percentage		10.00%	10.00%	10.00%	10.00%
Customer Concentration Risk [Member] \| Commissions receivable [Member]
Class of Stock [Line Items]
Concentration risk percentage		10.00%	10.00%	10.00%	10.00%
International Revenues [Member] \| Geographic Concentration Risk [Member] \| Total revenues [Member] \| Maximum [Member]
Class of Stock [Line Items]
Concentration risk percentage		1.00%	1.00%	1.00%	1.00%

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