Annual report pursuant to Section 13 and 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 12 Months Ended
Nov. 30, 2016
Aug. 31, 2016
May 31, 2016
Mar. 31, 2016
Feb. 29, 2016
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Class Of Stock [Line Items]                  
Stock issued upon vesting of stock units   2016-08     2016-02        
Common stock conversion date 2016-11 2016-08   2016-03          
Common stock issuance date     2016-05            
Common stock, shares outstanding           4,866,303 4,695,014 4,520,000 4,465,000
Class B common stock issued   241,628 9,198   4,911        
Cancellation of Class B common stock upon conversion of Class B units to Class A common stock           84,000 211,000 246,000  
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 (25,172) (21,200)   (38,076)