Annual report pursuant to Section 13 and 15(d)

Earnings (Loss) Per Share - Additional Information (Detail)

v2.4.0.6
Earnings (Loss) Per Share - Additional Information (Detail) (Stock Option Awards [Member])
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Stock Option Awards [Member]
     
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive shares 301,200 409,875 401,561