Quarterly report pursuant to Section 13 or 15(d)

Related-Party Transactions - Additional Information (Detail)

v3.20.1
Related-Party Transactions - Additional Information (Detail) - USD ($)
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Dec. 31, 2019
Related Party Transaction [Line Items]      
Operating lease cost $ 6,263,000 $ 5,909,000  
Aggregate principal amount for employee notes receivable 598,000   $ 388,000
MMC [Member]      
Related Party Transaction [Line Items]      
Real estate brokerage commissions and financing fees from transactions with subsidiaries of Marcus & Millichap Company 766,000 882,000  
Commission expenses for transactions with subsidiaries of Marcus & Millichap Company 453,000 522,000  
Operating lease cost 333,000 333,000  
Accounts payable and other liabilities - related party 86,000   $ 88,000
MMC [Member] | Transition Services Agreement [Member]      
Related Party Transaction [Line Items]      
Selling, general and administrative expense $ 26,000 $ 43,000  
George M. Marcus [Member]      
Related Party Transaction [Line Items]      
Beneficial ownership percentage 40.00%