Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share - Additional Information (Detail)

v2.4.1.9
Earnings Per Share - Additional Information (Detail)
 3 Months Ended
Mar. 31, 2015
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