Quarterly report pursuant to Section 13 or 15(d)

Related-Party Transactions - Additional Information (Detail)

v3.19.2
Related-Party Transactions - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Related Party Transaction [Line Items]          
Operating lease cost $ 6,106,000   $ 12,015,000    
Aggregate principal amount for employee notes receivable 415,000   415,000   $ 526,000
MMC [Member]          
Related Party Transaction [Line Items]          
Real estate brokerage commissions and financing fees from transactions with subsidiaries of Marcus & Millichap Company 1,900,000 $ 560,000 2,800,000 $ 3,100,000  
Commission expenses for transactions with subsidiaries of Marcus & Millichap Company 1,100,000 321,000 1,600,000 1,800,000  
Operating lease cost 333,000 255,000 $ 666,000 508,000  
Lease expiration date     May 31, 2022    
Accounts payable and other liabilities - related party 92,000   $ 92,000   $ 101,000
MMC [Member] | Transition Services Agreement [Member]          
Related Party Transaction [Line Items]          
Selling, general and administrative expense $ 32,000 $ 55,000 $ 75,000 $ 127,000  
George M. Marcus [Member]          
Related Party Transaction [Line Items]          
Beneficial ownership percentage     40.00%