Stockholders' Equity - Cost of Net Revenues and Operating Expenses Include Stock-Based Compensation (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total stock-based compensation expense $ 1,607 $ 1,706
Cost of net revenue [Member]    
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total stock-based compensation expense 49 163
Sales and marketing [Member]    
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total stock-based compensation expense 269 300
Technology and development [Member]    
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total stock-based compensation expense 81 180
General and administrative [Member]    
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]    
Total stock-based compensation expense $ 1,208 $ 1,063