Consolidated Statements of Shareholders Equity Statement (USD $)
In Thousands, except Share data
Total
Convertible Preferred Stock
Common Stock (Class A and B)
Additional Paid-in Capital
Accumulated Other Comprehensive Loss
Retained Earnings (Accumulated Deficit)
Balances, period start at Dec. 31, 2010 $ (4,890) $ 20,031 $ 3 $ 1,671 $ 0 $ (6,564)
Balances (in shares), period start at Dec. 31, 2010   17,416,317 32,979,881      
Issuance of common stock upon exercise of stock options, shares     155,968      
Issuance of common stock upon exercise of stock options 85   1 84    
Stock-based compensation expense 1,448     1,448    
Excess tax benefit from stock-based compensation 9     9    
Repurchase of common stock, shares     (51,000)      
Repurchase of common stock (308)     (308)    
Net income (loss) 3,379     0   3,379
Balances, period end at Dec. 31, 2011 (277) 20,031 4 2,904 0 (3,185)
Balances (in shares), period end at Dec. 31, 2011   17,416,317 33,084,849      
Issuance of common stock upon exercise of stock options, shares     1,082,288      
Issuance of common stock upon exercise of stock options 606     606    
Stock-based compensation expense 4,796     4,796    
Excess tax benefit from stock-based compensation 1,541     1,541    
Donation of common shares, shares 150,000   150,000      
Donation of common shares 1,851     1,851    
Other comprehensive loss (1)       (1)  
Net income (loss) 1,427         1,427
Balances, period end at Dec. 31, 2012 9,943 20,031 4 11,698 (1) (1,758)
Balances (in shares), period end at Dec. 31, 2012   17,416,317 34,317,137      
Issuance of common stock upon exercise of stock options, shares 4,182,114          
Proceeds from public offering, net of underwriters' discount, shares     6,230,000      
Proceeds from public offering, net of underwriters' discount 176,975   1 176,974    
Conversion of preferred stock to common stock, shares   (17,416,317) 17,416,317      
Conversion of preferred stock to common stock 20,031 (20,031) 1 20,030    
Issuance of common stock upon exercise of stock options and warrants, shares     4,235,232      
Issuance of common stock upon exercise of stock options and warrants 10,523   1 10,522    
Stock-based compensation expense 14,457     14,457    
Excess tax benefit from stock-based compensation 5,725     5,725    
Other comprehensive loss (70)       (70)  
Net income (loss) 7,076         7,076
Balances, period end at Dec. 31, 2013 $ 244,660 $ 0 $ 7 $ 239,406 $ (71) $ 5,318
Balances (in shares), period end at Dec. 31, 2013   0 62,198,686