Convertible Preferred Stock
 12 Months Ended
Dec. 31, 2015
Temporary Equity, Other Disclosures [Abstract]  
Convertible Preferred Stock
Convertible Preferred Stock
As described in Note 1, on the Closing Date, the Company completed an IPO of its common stock. Upon the completion of the IPO, all outstanding shares of the Company’s convertible preferred stock were automatically converted into an aggregate of 14,848,824 shares of common stock.
The following table summarizes the issuances of convertible preferred stock subject to conversion as of the IPO completion:
 
Number of Shares
Authorized
 
Number of Shares
Outstanding
 
Original Issue and
Conversion Price
per Share
Series A convertible preferred stock
2,486,507

 
2,383,745

 
$
0.582

Series B convertible preferred stock
3,649,368

 
3,649,368

 
$
0.84656

Series C convertible preferred stock
5,406,501

 
5,406,501

 
$
1.4798

Series D convertible preferred stock
3,409,250

 
3,409,210

 
$
3.8132

Total convertible preferred stock
14,951,626

 
14,848,824

 
 

The Series A, Series B, Series C and Series D convertible preferred stock are collectively referred to as the "Preferred Stock," and individually as the "Series A," "Series B," "Series C," and "Series D." The "Original Issue Price" per share excludes the cost of issuance.
Prior to the consummation of the IPO, the Company had determined that its convertible preferred stock was contingently redeemable due to the existence of deemed liquidation provisions contained in its former certificate of incorporation, and therefore classified its convertible preferred stock outside of permanent equity.
Summary of Activity
The following table presents a summary of activity for the convertible preferred stock issued and outstanding for the years ended December 31, 2013, 2014 and 2015 (in thousands):
 
Convertible Preferred Stock
 
Series A
 
Series B
 
Series C
 
Series D
 
Total Amount
Balance as of December 31, 2013
$
1,387

 
$
3,089

 
$
8,000

 
$
13,000

 
$
25,476

 
 
 
 
 
 
 
 
 
 
Balance as of December 31, 2014
1,387

 
3,089

 
8,000

 
13,000

 
25,476

 
 
 
 
 
 
 
 
 
 
Conversion to common stock upon IPO
(1,387
)
 
(3,089
)
 
(8,000
)
 
(13,000
)
 
(25,476
)
Balance as of December 31, 2015
$
—

 
$
—

 
$
—

 
$
—

 
$
—

 
Conversion Rights
The holders of the Company's Preferred Stock were entitled to convert their shares into common stock at any time. The number of shares of common stock issued upon conversion was determined based on the number of converted Preferred Stock shares and the conversion price. The conversion price varied based upon the occurrence of certain events, such as stock splits, business combinations, issuances of common stock dividends and distributions, recapitalizations, mergers, consolidations and sales of common stock below the Preferred Stock conversion price. As of December 31, 2014, the conversion price of each series of Preferred Stock was equal to the Original Issue Price of such series.