Consolidated Statements of Changes in Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($)
$ in Thousands
Total
Common Stock [Member]
Additional Paid-in Capital [Member]
Accumulated Deficit [Member]
Treasury Stock [Member]
Series A Redeemable Convertible Preferred Stock [Member]
Series B Redeemable Convertible Preferred Stock [Member]
Series C Redeemable Convertible Preferred Stock [Member]
Series D Redeemable Convertible Preferred Stock [Member]
Beginning Balance at Dec. 31, 2012 $ (111,906) $ 125   $ (112,031)          
Temporary equity, Beginning Balance at Dec. 31, 2012           $ 34,793 $ 2,908 $ 57,190  
Beginning Balance, shares at Dec. 31, 2012   12,533,527              
Temporary equity, Beginning Balance, shares at Dec. 31, 2012           6,303,033 519,269 6,873,797  
Stock-based compensation expense 2,047   $ 2,047            
Accretion of preferred stock to redemption value           $ 20,169 $ 1,630 $ 11,754  
Accretion of preferred stock to redemption value (33,553)   (3,308) (30,245)          
Issuance of common stock warrants 1,007   1,007            
Issuance of common stock upon exercise of stock options $ 257 $ 3 254            
Issuance of common stock upon exercise of stock options, net of stock withheld for taxes, shares 239,407 229,994              
Temporary equity, Ending Balance at Dec. 31, 2013           $ 54,962 $ 4,538 $ 68,944  
Net loss $ (18,873)     (18,873)          
Ending Balance at Dec. 31, 2013 (161,021) $ 128   (161,149)          
Ending Balance, shares at Dec. 31, 2013   12,763,521              
Temporary equity, Ending Balance, shares at Dec. 31, 2013           6,303,033 519,269 6,873,797  
Stock-based compensation expense 2,159   2,159            
Accretion of preferred stock to redemption value           $ 13,930 $ 1,143 $ 11,342 $ 25,921
Accretion of preferred stock to redemption value (52,336)   (2,650) (49,686)          
Issuance of Series D redeemable convertible preferred stock, net of issuance costs                 $ 30,818
Issuance of common stock upon exercise of stock options $ 489 $ 2 487            
Issuance of common stock upon exercise of stock options, net of stock withheld for taxes, shares 201,200 201,200              
Purchase of common stock $ (3,526) $ (4) 4   $ (3,526)        
Purchase of common stock, shares   (401,626)     401,626        
Issuance of common stock in relation to IPO and concurrent private placement, net of offering costs , shares                 2,686,516
Temporary equity, Ending Balance at Dec. 31, 2014           $ 68,892 $ 5,681 $ 80,286 $ 56,739
Net loss (32,627)     (32,627)          
Ending Balance at Dec. 31, 2014 (246,862) $ 126   (243,462) $ (3,526)        
Ending Balance, shares at Dec. 31, 2014   12,563,095     401,626        
Temporary equity, Ending Balance, shares at Dec. 31, 2014           6,303,033 519,269 6,873,797 2,686,516
Stock-based compensation expense 10,685   10,685            
Accretion of preferred stock to redemption value           $ 14,308 $ 1,173 $ 10,929 $ 8,651
Accretion of preferred stock to redemption value (35,061)   (2,203) (32,858)          
Conversion of preferred stock to common stock           $ (83,200) $ (6,854) $ (91,215) $ (65,390)
Conversion of preferred stock to common stock $ 246,659 $ 164 246,495            
Conversion of preferred stock to common stock, shares           (6,303,033) (519,269) (6,873,797) (2,686,516)
Conversion of preferred stock to common stock, shares   16,382,615              
Issuance of common stock upon exercise of stock options, net of stock withheld for taxes, shares 385,328                
IPO participation payment and beneficial conversion charge   $ 19 14,142 (14,161)          
IPO participation payment and beneficial conversion charge, shares   1,939,990              
Issuance of common stock in relation to IPO and concurrent private placement, net of offering costs $ 112,275 $ 77 112,198            
Issuance of common stock in relation to IPO and concurrent private placement, net of offering costs , shares   7,730,000              
Issuance of common stock and options associated with acquisitions 31,975 $ 13 31,962            
Issuance of common stock and options associated with acquisitions, shares   1,261,718              
Issuance of restricted stock   $ 13 (13)            
Issuance of restricted stock, shares   1,358,505              
Shares withheld for employee taxes (3,087) $ (1) (3,086)            
Shares withheld for employee taxes, shares   (134,296)              
Issuance of common stock upon exercise of stock options and warrants 1,348 $ 4 1,344            
Issuance of common stock upon exercise of stock options and warrants, shares   438,773              
Net loss (49,857)     (49,857)          
Ending Balance at Dec. 31, 2015 $ 68,075 $ 415 $ 411,524 $ (340,338) $ (3,526)        
Ending Balance, shares at Dec. 31, 2015   41,540,400     401,626        
Temporary equity, Ending Balance, shares at Dec. 31, 2015           0 0 0 0