Quarterly report pursuant to Section 13 or 15(d)

Related-Party Transactions - Additional Information (Detail)

v3.10.0.1
Related-Party Transactions - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Related Party Transaction [Line Items]          
Aggregate principal amount for employee notes receivable $ 398,000   $ 398,000   $ 621,000
MMC [Member]          
Related Party Transaction [Line Items]          
Real estate brokerage commissions and financing fees from transactions with subsidiaries of Marcus & Millichap Company 560,000 $ 120,000 3,100,000 $ 323,000  
Commission expenses for transactions with subsidiaries of Marcus & Millichap Company 321,000 65,000 1,800,000 187,000  
Rent expense for lease 255,000 253,000 $ 508,000 506,000  
Lease expiration date     May 31, 2022    
Accounts payable and other liabilities - related party 105,000   $ 105,000   $ 91,000
MMC [Member] | Transition Services Agreement [Member]          
Related Party Transaction [Line Items]          
Selling, general and administrative expense $ 55,000 $ 43,000 $ 127,000 $ 125,000  
Transition services agreement date     Oct. 01, 2013    
George M. Marcus [Member]          
Related Party Transaction [Line Items]          
Beneficial ownership percentage     44.00%