Information Regarding Net Revenue by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Net revenue	$ 20,022	$ 15,432	$ 56,844	$ 43,664
Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of net revenue	100.00%	100.00%	100.00%	100.00%
Americas
Segment Reporting Information [Line Items]
Net revenue	$ 15,035	$ 10,291	$ 44,172	$ 28,894
Americas | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of net revenue	75.00%	67.00%	78.00%	66.00%
Europe and the Middle East
Segment Reporting Information [Line Items]
Net revenue	$ 2,161	$ 1,771	$ 6,992	$ 5,767
Europe and the Middle East | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of net revenue	11.00%	11.00%	12.00%	13.00%
Asia-Pacific
Segment Reporting Information [Line Items]
Net revenue	$ 2,826	$ 3,370	$ 5,680	$ 9,003
Asia-Pacific | Geographic Concentration Risk | Revenue from Contract with Customer
Segment Reporting Information [Line Items]
Percentage of net revenue	14.00%	22.00%	10.00%	21.00%