Quarterly report pursuant to Section 13 or 15(d)

Stockholders' Equity - Additional Information (Detail)

v3.3.0.814
Stockholders' Equity - Additional Information (Detail) - shares
 3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Sep. 24, 2015
Dec. 31, 2014
Class B Common Stock [Member]            
Class of Stock [Line Items]            
Certain Class B stockholders converted into Class A 1,908,000 0 5,131,296 899,328    
Common Stock, shares authorized 75,000,000   75,000,000     75,000,000
Class B Common Stock [Member] | Minimum [Member]            
Class of Stock [Line Items]            
Common Stock, shares authorized         60,000,000  
Class B Common Stock [Member] | Maximum [Member]            
Class of Stock [Line Items]            
Common Stock, shares authorized         75,000,000  
Class A Common Stock [Member]            
Class of Stock [Line Items]            
Shares issued as a part of conversion 1,908,000 0 5,131,296 899,328    
Common Stock, shares authorized 500,000,000   500,000,000     500,000,000
Class A Common Stock [Member] | Minimum [Member]            
Class of Stock [Line Items]            
Common Stock, shares authorized         100,000,000  
Class A Common Stock [Member] | Maximum [Member]            
Class of Stock [Line Items]            
Common Stock, shares authorized         500,000,000