XML 89 R76.htm IDEA: XBRL DOCUMENT v3.20.4
Stockholders' Equity - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Class of Stock [Line Items]    
Condition of electing directors by class a and class b common stock vote In the election of directors, the holders of Class A common stock are entitled by class vote, exclusive of other stockholders, to elect two of the Company’s directors, with each Class A share being entitled to one vote. In the election of the other seven directors and all other matters submitted to the stockholders for a vote, the holders of Class A shares and Class B shares shall vote as a single class, with each Class A share being entitled to one vote and each Class B share entitled to ten votes.  
Payments for treasury stock $ 65,951 $ 214,735
Payments for treasury stock, shares 37,106  
Cash dividends paid $ 2,795,504 $ 5,539,608