Quarterly report pursuant to Section 13 or 15(d)

Stock Option Information (Detail)

v2.4.0.8
Stock Option Information (Detail) (USD $)
 6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Shares    
Beginning Balance 1,927,099 2,106,674
Granted 735,750  
Exercised (170,745)  
Forfeited or expired (81,774)  
Ending Balance 2,410,330 2,106,674
Exercisable at end of period 635,389  
Expected to Vest 1,685,306  
Weighted Average Exercise Price    
Beginning Balance $ 4.37  
Granted $ 6.93  
Exercised $ 3.36  
Forfeited or expired $ 11.94  
Ending Balance $ 4.97  
Exercisable at end of period $ 6.13  
Expected to Vest $ 4.55  
Weighted Average Grant Date Fair value    
Beginning Balance $ 3.45  
Granted $ 4.90  
Exercised $ 5.56  
Forfeited or expired $ 7.23  
Ending Balance $ 3.62  
Exercisable at end of period $ 4.55  
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 9 months 18 days  
Exercisable at end of period 2 years 10 months 24 days  
Expected to Vest 6 years 9 months 18 days  
Aggregate Intrinsic Value    
Beginning Balance $ 3,899  
Granted     
Exercised     
Forfeited or expired     
Ending Balance 7,016  
Exercisable at end of period 1,793  
Expected to Vest $ 4,960