Quarterly report pursuant to Section 13 or 15(d)

Stock Option Information (Detail)

v2.4.0.8
Stock Option Information (Detail) (USD $)
 9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Shares    
Beginning Balance 1,927,099 2,089,524
Granted 735,750  
Exercised (283,405)  
Forfeited or expired (83,424)  
Ending Balance 2,296,020 2,089,524
Exercisable at end of period 639,204  
Expected to Vest 1,573,147  
Weighted Average Exercise Price    
Beginning Balance $ 4.37  
Granted $ 6.93  
Exercised $ 3.42  
Forfeited or expired $ 12.08  
Ending Balance $ 5.03  
Exercisable at end of period $ 5.87  
Expected to Vest $ 4.70  
Weighted Average Grant Date Fair value    
Beginning Balance $ 3.45  
Granted $ 4.90  
Exercised $ 2.36  
Forfeited or expired $ 7.31  
Ending Balance $ 3.54  
Exercisable at end of period $ 4.22  
Expected to Vest $ 3.28  
Weighted Average Remaining Contractual Term    
Outstanding at beginning of period 5 years 4 months 24 days  
Outstanding at end of period 5 years 8 months 12 days  
Exercisable at end of period 3 years 1 month 6 days  
Expected to Vest 6 years 7 months 6 days  
Aggregate Intrinsic Value    
Beginning Balance $ 8,697  
Granted 994  
Exercised 1,201  
Forfeited or expired 59  
Ending Balance 8,255  
Exercisable at end of period 2,331  
Expected to Vest $ 5,625