Information Regarding Net Revenue by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net revenue	$ 15,432	$ 15,560	$ 43,664	$ 41,521
Percentage of net revenue	100.00%	100.00%	100.00%	100.00%
Americas
Segment Reporting Information [Line Items]
Net revenue	$ 10,291	$ 9,924	$ 28,894	$ 27,343
Percentage of net revenue	67.00%	64.00%	66.00%	66.00%
Europe And Middle East
Segment Reporting Information [Line Items]
Net revenue	$ 1,771	$ 2,834	$ 5,767	$ 6,654
Percentage of net revenue	11.00%	18.00%	13.00%	16.00%
Asia-Pacific
Segment Reporting Information [Line Items]
Net revenue	$ 3,370	$ 2,802	$ 9,003	$ 7,524
Percentage of net revenue	22.00%	18.00%	21.00%	18.00%