Earnings Per Share (Details) (USD $)
3 Months Ended 6 Months Ended
Jun. 30, 2014
Jun. 30, 2013
Jun. 30, 2014
Jun. 30, 2013
Anti-dilutive sercurities excluded from the calculation of earnings per share:        
Net income $ 4,244,217 $ 4,122,617 $ 6,674,176 $ 7,099,249
Denominatior for basic earnings per share-weighted-average shares (in shares) 23,017,056 22,857,339 22,992,087 22,826,908
Employee stock options/Unvested Restricted Stock (in shares) 489,412 498,714 485,936 471,205
Denominator for dilutive earnings per share (in shares) 23,506,468 23,356,053 23,478,023 23,298,113
Basic net income per common share (USD per share) $ 0.18 $ 0.18 $ 0.29 $ 0.31
Diluted net income per common share (USD per share) $ 0.18 $ 0.18 $ 0.28 $ 0.30
Stock Options [Member]
       
Anti-dilutive sercurities excluded from the calculation of earnings per share:        
Stock options excluded from the calculation of diluted earnings per share (in shares)     0 0