v3.10.0.1
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, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Apr. 01, 2013
Numerator:          
Net loss attributable to common stockholders, basic and diluted $ (522) $ (3,450) $ (1,636) $ (18,347)  
Denominator:          
Weighted average common stock, basic and diluted (in shares) 42,377 40,336 41,890 39,468  
Net loss per share attributable to common stockholders:          
Basic and diluted (in dollars per share) $ (0.01) $ (0.09) $ (0.04) $ (0.46)  
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