Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Details)

v2.4.0.6
Stock-Based Compensation (Details) (USD $)
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock compensation expense $ 2,304,118 $ 3,592,090 $ 597,672
Weighted-average grant date fair value of options granted $ 1.86 $ 2.22 $ 1.13
Options exercised in period 1,232,001 2,697,833 491,667
Aggregate intrinsic value of options exercised in period 3,360,686 9,620,085 697,662
Issued stock upon exercise of stock options, net, shares 1,225,270 1,832,673 350,156
Proceeds from exercise of options 752,060 225,010 32,550
Payment of withholding tax related to stock options exercised 8,765 2,762,710 133,153
Aggregate fair value of vested stock options 460,000 998,000 379,000
Unrecognized compensation cost related to unvested stock-based awards 2,200,000    
Unrecognized compensation cost related to unvested stock-based awards, weighted average recognition period 2 years    
Restricted Stock [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of restricted stock units vested during period 30,000 1,050,000  
Aggregate fair value of vested restricted stock $ 85,000 $ 4,200,000