Annual report pursuant to Section 13 and 15(d)

Stock Compensation Plans - Additional Information (Details)

v3.3.1.900
Stock Compensation Plans - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Issuance of common stock $ 2,016 $ 3,282 $ 1,256
Granted (in shares) 15,236,333    
Total compensation cost not yet recognized, stock options $ 9,632    
Unrecognized compensation cost for stock based compensation, period of recognition 1 year 11 months 19 days    
Options, exercises in period, total intrinsic value $ 2,595 4,640 957
Allocated share-based compensation expense $ 8,759 $ 10,541 $ 6,766
Qualified Employee Stock Purchase Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares available for grant (in shares) 10,000,000    
Offering date (percent) 5.00%    
Stock issued during period, gross (in shares) 192,978 89,581 112,646
Shares authorized under stock option plans, exercise price range, lower range limit (per share) $ 2.00 $ 2.87 $ 1.57
Shares authorized under stock option plans, exercise price range, upper range limit (per share) $ 3.67 $ 4.03 $ 2.97
Issuance of common stock $ 545 $ 291 $ 201
Plan 1999      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares available for grant (in shares) 1,244,354    
Plan 1999 | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granted (in shares) 25,000,000    
Awards with annual limit (in shares) 1,500,000    
Plan 2009      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares available for grant (in shares) 20,009,745    
Granted (in shares) 1,810,000    
Combined voting power (percent) 10.00%    
Fair market value (percent) 100.00%    
Fair market value for ten percent shareholder (percent) 110.00%    
Plan 2009 | Maximum      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granted (in shares) 45,000,000    
Employees and Director Option      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Options, grants in period, weighted average grant date fair value (per share) $ 2.79 $ 1.85 $ 0.74
Restricted Stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 4 years    
Fair value of stock vested $ 42