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) (Stock option awards [Member])
3 Months Ended 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Sep. 30, 2013
Sep. 30, 2012
Stock option awards [Member]
       
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Anti-dilutive shares 65,525 80,825 370,525 122,525