Earnings Per Share
 12 Months Ended
Dec. 31, 2015
Earnings Per Share [Abstract]  
Earnings Per Share
Earnings Per Share
Diluted loss per share is the same as basic loss per share for the years ended December 31, 2013, 2014 and 2015 because the effects of potentially dilutive items were anti-dilutive given the Company’s net losses in those periods.
The following securities have been excluded from the calculation of weighted-average common shares outstanding because the effect is anti-dilutive for the years ended December 31:  
 
2013
 
2014
 
2015
Convertible preferred stock:
 
 
 
 
 
Series A
2,383,745

 
2,383,745

 
—

Series B
3,649,368

 
3,649,368

 
—

Series C
5,406,501

 
5,406,501

 
—

Series D
3,409,210

 
3,409,210

 
—

Common stock subject to repurchase
6,457

 
5,000

 
—

Lender Warrants and Additional Lender Warrant to purchase common stock
—

 
150,000

 
200,000

2015 ESPP
—

 
—

 
192,883

Stock options
2,374,241

 
3,425,117

 
4,297,893