Net loss per share attributable to common stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands |
3 Months Ended | ||
|---|---|---|---|
Mar. 31, 2017 |
Mar. 31, 2016 |
Apr. 01, 2013 |
|
| Numerator: | |||
| Net loss attributable to common stockholders, basic and diluted | $ (6,880) | $ (9,984) | |
| Denominator: | |||
| Weighted average number of common stock, basic and diluted (in shares) | 38,712 | 37,554 | |
| Net loss per share attributable to common stockholders: | |||
| Basic and diluted (in dollars per share) | $ (0.18) | $ (0.27) | |
| Stock repurchase program | |||
| Remaining approved amount for repurchases | $ 5,180 | ||
| Maximum | |||
| Stock repurchase program | |||
| Amount of common stock approved by the entity for a stock repurchase program | $ 10,000 | ||