Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share - Additional Information (Detail)

v2.4.0.6
Earnings Per Share - Additional Information (Detail) (Stock Option Awards [Member])
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Stock Option Awards [Member]
   
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Anti-dilutive shares 76,625 373,650