Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation (Details)

v2.4.0.8
Stock-Based Compensation (Details) (USD $)
 1 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Jun. 30, 2013
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Jul. 31, 2013
Restricted Stock [Member]
Apr. 30, 2013
Restricted Stock [Member]
Mar. 31, 2013
Restricted Stock [Member]
Feb. 28, 2013
Restricted Stock [Member]
Dec. 31, 2013
Restricted Stock [Member]
Dec. 31, 2012
Restricted Stock [Member]
Dec. 31, 2011
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                      
Options cancelled in period 50,000                    
Stock compensation expense   $ (2,908,269) $ (2,304,118) $ (3,592,090)              
Weighted-average grant date fair value of options granted   $ 1.81 $ 1.86 $ 2.22              
Options exercised in period   60,000 1,232,001 2,697,833              
Aggregate intrinsic value of options exercised in period   126,000 3,400,000 9,600,000              
Issued stock upon exercise of stock options, net, shares   39,649 1,225,271 1,832,673              
Proceeds from exercise of options   39,000 752,000 225,000              
Payment of withholding tax related to stock options exercised   659,018 8,765 2,762,710              
Aggregate fair value of vested stock options   36,000 460,000 998,000              
Number of restricted stock units vested during period           85,000 560,000 100,000 745,000 30,000 1,050,000
Aggregate fair value of vested restricted stock           224,000 1,800,000 308,000 2,300,000 85,000 4,200,000
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   1 year 11 months 15 days                  
Number of restricted stock units forfeited during period         29,250       29,250    
Aggregate fair value of restricted stock units forfeited during period         $ 83,000