Quarterly report pursuant to Section 13 or 15(d)

Related-Party Transactions - Additional Information (Detail)

v3.20.2
Related-Party Transactions - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Related Party Transaction [Line Items]          
Operating lease cost $ 6,341,000 $ 6,106,000 $ 12,604,000 $ 12,015,000  
Aggregate principal amount for employee notes receivable 576,000   576,000   $ 388,000
MMC [Member]          
Related Party Transaction [Line Items]          
Real estate brokerage commissions and financing fees from transactions with subsidiaries of Marcus & Millichap Company 880,000 1,900,000 1,600,000 2,800,000  
Commission expenses for transactions with subsidiaries of Marcus & Millichap Company 536,000 1,100,000 988,000 1,600,000  
Operating lease cost 332,000 333,000 665,000 666,000  
Accounts payable and other liabilities - related party 94,000   94,000   $ 88,000
MMC [Member] | Transition Services Agreement [Member]          
Related Party Transaction [Line Items]          
Selling, general and administrative expense $ 16,000 $ 32,000 $ 42,000 $ 75,000  
George M. Marcus [Member]          
Related Party Transaction [Line Items]          
Beneficial ownership percentage     40.00%