Net Loss per Share (Details 2) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Numerator | |||||||||||
| Net loss attributable to holders of common stock | $ (26,733) | $ (29,088) | $ (28,300) | ||||||||
| Denominator: | |||||||||||
| Weighted-average shares of common stock outstanding, basic and diluted | 45,651,475 | 41,645,894 | 41,362,476 | 40,978,741 | 40,577,087 | 40,269,937 | 39,304,884 | 7,698,709 | 42,420,356 | 32,075,107 | 7,432,055 |
| Net loss per share attributable to holders of common stock, basic and diluted (in dollars per share) | $ (0.07) | $ (0.20) | $ (0.23) | $ (0.13) | $ (0.10) | $ (0.18) | $ (0.27) | $ (0.92) | $ (0.63) | $ (0.91) | $ (3.81) |