Net loss per share attributable to common stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
|
| Numerator: | ||||
| Net loss attributable to common stockholders, basic and diluted | $ (5,937) | $ (3,734) | $ (13,819) | $ (9,182) |
| Denominator: | ||||
| Weighted average common stock, basic and diluted (in shares) | 36,724 | 35,621 | 36,558 | 35,486 |
| Net loss per share attributable to common stockholders: | ||||
| Basic and diluted (in dollars per share) | $ (0.16) | $ (0.10) | $ (0.38) | $ (0.26) |