Consolidated Statements of Stockholders' Equity (USD $)
In Thousands, except Share data
Common Stock [Member]
Additional Paid-in Capital [Member]
Retained Earnings [Member]
Accumulated Other Comprehensive Income (Loss) [Member]
Total
Balance at Dec. 31, 2011 $ 28 $ 190,314 $ (32,713) $ 775 $ 158,404
Balance (in Shares) at Dec. 31, 2011 27,882,223        
Issuance of common stock from exercise of stock options 1 1,827     1,828
Issuance of common stock from exercise of stock options (in Shares) 670,734        
Issuance of common stock from restricted stock unit grant   (325)     (325)
Issuance of common stock from restricted stock unit grant (in Shares) 76,001        
Issuance of common stock from employee stock purchase plan   943     943
Issuance of common stock from employee stock purchase plan (in Shares) 101,088       101,088
Income tax benefit from stock option exercises   51     51
Stock-based compensation expense   12,459     12,459
Net income (loss)     (20,691)   (20,691)
Other comprehensive income (loss), net       296 296
Balance at Dec. 31, 2012 29 205,269 (53,404) 1,071 152,965
Balance (in Shares) at Dec. 31, 2012 28,730,046        
Issuance of common stock from exercise of stock options and warrant 1 2,904     2,905
Issuance of common stock from exercise of stock options and warrant (in Shares) 854,379        
Issuance of common stock from restricted stock unit grant   (2,180)     (2,180)
Issuance of common stock from restricted stock unit grant (in Shares) 380,940        
Issuance of common stock from employee stock purchase plan   2,221     2,221
Issuance of common stock from employee stock purchase plan (in Shares) 279,074       279,074
Income tax benefit adjustment from stock option exercises   (185)     (185)
Stock-based compensation expense   16,978     16,978
Net income (loss)     (13,178)   (13,178)
Other comprehensive income (loss), net       (133) (133)
Balance at Dec. 31, 2013 30 225,007 (66,582) 938 159,393
Balance (in Shares) at Dec. 31, 2013 30,244,439        
Issuance of common stock from exercise of stock options 1 4,297     4,298
Issuance of common stock from exercise of stock options (in Shares) 788,196       788,196
Issuance of common stock from restricted stock unit grant 1 (4,965)     (4,964)
Issuance of common stock from restricted stock unit grant (in Shares) 738,862        
Issuance of common stock from employee stock purchase plan   2,668     2,668
Issuance of common stock from employee stock purchase plan (in Shares) 264,886       264,886
Income tax benefit from stock option exercises   55     55
Stock-based compensation expense   22,460     22,460
Issuance of stock from Cortina acquisition 5 77,953     77,958
Issuance of stock from Cortina acquisition (in Shares) 5,274,580        
Net income (loss)     (22,608)   (22,608)
Other comprehensive income (loss), net       (86) (86)
Balance at Dec. 31, 2014 $ 37 $ 327,475 $ (89,190) $ 852 $ 239,174
Balance (in Shares) at Dec. 31, 2014 37,310,963