Classification of Compensation Expense Associated with Share-Based Payments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 379	$ 834
Cost Of Revenue
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense	40	70
Sales and Marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense	73	134
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense	193	551
Engineering And Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 73	$ 79