Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Summary of Redeemable Convertible Preferred Stock (Details)

v3.3.1.900
Stockholders' Equity - Summary of Redeemable Convertible Preferred Stock (Details)
12 Months Ended
Dec. 31, 2015
Dec. 31, 2013
$ / shares
shares
Series B Redeemable Convertible Preferred Stock    
Temporary Equity [Line Items]    
Shares authorized   500,000
Shares issued   425,511
Par value | $ / shares   $ 0.001
Conversion rate   1.45108
Liquidation preference per share | $ / shares   $ 11.880
Dividend rate   5.00%
Issue date 2003-07  
Redemption date   Jan. 01, 2016
Series C Redeemable Convertible Preferred Stock    
Temporary Equity [Line Items]    
Shares authorized   400,000
Shares issued   365,903
Par value | $ / shares   $ 0.001
Conversion rate   1.73014
Liquidation preference per share | $ / shares   $ 17.580
Dividend rate   8.00%
Issue date 2004-06  
Redemption date   Jan. 01, 2016
Series D Redeemable Convertible Preferred Stock    
Temporary Equity [Line Items]    
Shares authorized   1,700,000
Shares issued   1,573,126
Par value | $ / shares   $ 0.001
Conversion rate   1.87951
Liquidation preference per share | $ / shares   $ 21.900
Dividend rate   8.00%
Redemption date   Jan. 01, 2016
Series D Redeemable Convertible Preferred Stock | Minimum    
Temporary Equity [Line Items]    
Issue date 2005-07  
Series D Redeemable Convertible Preferred Stock | Maximum    
Temporary Equity [Line Items]    
Issue date 2007-07  
Series E Redeemable Convertible Preferred Stock    
Temporary Equity [Line Items]    
Shares authorized   1,700,000
Shares issued   1,634,874
Par value | $ / shares   $ 0.001
Conversion rate   2.69244
Liquidation preference per share | $ / shares   $ 19.224
Dividend rate   8.00%
Redemption date   Jan. 01, 2016
Series E Redeemable Convertible Preferred Stock | Minimum    
Temporary Equity [Line Items]    
Issue date 2007-10  
Series E Redeemable Convertible Preferred Stock | Maximum    
Temporary Equity [Line Items]    
Issue date 2009-02  
Series F Redeemable Convertible Preferred Stock    
Temporary Equity [Line Items]    
Shares authorized   2,800,000
Shares issued   2,701,957
Par value | $ / shares   $ 0.001
Conversion rate   1.00000
Liquidation preference per share | $ / shares   $ 7.140
Dividend rate   8.00%
Redemption date   Jan. 01, 2016
Series F Redeemable Convertible Preferred Stock | Minimum    
Temporary Equity [Line Items]    
Issue date 2010-02  
Series F Redeemable Convertible Preferred Stock | Maximum    
Temporary Equity [Line Items]    
Issue date 2010-06  
Series G Redeemable Convertible Preferred Stock    
Temporary Equity [Line Items]    
Shares authorized   2,900,000
Shares issued   2,840,260
Par value | $ / shares   $ 0.001
Conversion rate   1.00000
Liquidation preference per share | $ / shares   $ 14.083
Dividend rate   8.00%
Issue date 2012-03  
Redemption date   Jan. 01, 2016
Redeemable Convertible Preferred Stock    
Temporary Equity [Line Items]    
Shares authorized   10,000,000
Shares issued   9,541,631