Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share - Additional Information (Detail)

v2.4.0.8
Earnings Per Share - Additional Information (Detail)
3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Options excluded from the computation of diluted earnings 0 0 0 0
Class A Common Stock [Member]
       
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Common stock, voting rights     One vote per share  
Class B Common Stock [Member]
       
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Common stock, voting rights     Ten votes per share