Net loss per share attributable to common stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
Apr. 01, 2013 |
|
| Numerator: | |||||
| Net loss attributable to common stockholders, basic and diluted | $ (3,450) | $ (5,709) | $ (18,347) | $ (22,959) | |
| Denominator: | |||||
| Weighted average common stock, basic and diluted (in shares) | 40,336 | 38,189 | 39,468 | 37,897 | |
| Net loss per share attributable to common stockholders: | |||||
| Basic and diluted (in dollars per share) | $ (0.09) | $ (0.15) | $ (0.46) | $ (0.61) | |
| Stock repurchase program | |||||
| Remaining approved amount for repurchases | $ 5,180 | $ 5,180 | |||
| Maximum | |||||
| Stock repurchase program | |||||
| Amount of common stock approved by the entity for a stock repurchase program | $ 10,000 | ||||