Quarterly report pursuant to Section 13 or 15(d)

Common Stock - Summary of Stock Options Activity (Detail)

v2.4.0.8
Common Stock - Summary of Stock Options Activity (Detail) (USD $)
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]    
Number of Optioned Common Shares, Beginning Balance 804,781  
Number of Optioned Common Shares, Option grants 209,282  
Number of Optioned Common Shares, Option expirations (3,061)  
Number of Optioned Common Shares, Option exercises (3,475) (116,834)
Number of Optioned Common Shares, Option forfeitures (21,911)  
Number of Optioned Common Shares, Ending Balance 985,616  
Weighted Average Exercise Price, Beginning Balance $ 11.34  
Weighted Average Exercise Price, Option grants $ 11.81  
Weighted Average Exercise Price, Option expirations $ 4.11  
Weighted Average Exercise Price, Option exercises $ 3.00  
Weighted Average Exercise Price, Option forfeitures $ 14.30  
Weighted Average Exercise Price, Ending Balance $ 11.42