Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share - Additional Information (Detail)

v3.20.2
Earnings Per Share - Additional Information (Detail) - $ / shares
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Dec. 31, 2019
Earnings Per Share [Line Items]          
Shares excluded from the computation of diluted earnings 88,577 6,454 108,328 101,992  
Class A Common Stock [Member]          
Earnings Per Share [Line Items]          
Common Stock, par value $ 0.001   $ 0.001   $ 0.001
Common stock, voting rights     one vote per share    
Class B Common Stock [Member]          
Earnings Per Share [Line Items]          
Common Stock, par value $ 0.001   $ 0.001   $ 0.001
Common stock, voting rights     ten votes per share