Net loss per share attributable to common stockholders (Details 2) - USD ($) $ in Thousands |
Apr. 01, 2013 |
Jun. 30, 2015 |
|---|---|---|
| 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 |