Quarterly report pursuant to Section 13 or 15(d)

Equity - Class B Common Stock (Detail)

v3.7.0.1
Equity - Class B Common Stock (Detail) - Class B Common Stock - shares
 1 Months Ended 3 Months Ended
Mar. 31, 2017
Mar. 31, 2017
Mar. 31, 2016
Dec. 31, 2016
Dec. 31, 2015
Class Of Stock [Line Items]          
Common stock conversion date 2017-03        
Common stock, shares outstanding 4,840,295 4,840,295 4,662,000 4,866,303 4,695,000
Cancellation of Class B common stock upon conversion of Class B units to Class A common stock   26,000 38,000    
Resale And Registration Rights Agreement          
Class Of Stock [Line Items]          
Cancellation of Class B common stock upon conversion of Class B units to Class A common stock (26,008)