Information Regarding Net Revenue and Gross Profit by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Net revenue	$ 22,237	$ 20,294	$ 41,759	$ 36,822
Gross profit	$ 9,883	$ 8,153	$ 18,587	$ 14,661
Gross profit margin	44.00%	40.00%	45.00%	40.00%
Operating expenses:
Research and development	$ 2,078	$ 1,837	$ 4,104	$ 3,524
Selling and marketing	4,721	4,358	9,219	8,261
General and administrative	2,279	2,756	4,901	5,311
Restructuring and severance	(2)	258	(14)	368
Total operating expenses	9,076	9,209	18,210	17,464
Income (loss) from operations	807	(1,056)	377	(2,803)
Non-operating income (expense):
Interest expense, net	(241)	(472)	(520)	(948)
Loss on extinguishment of debt, net		(1,369)		(1,369)
Foreign currency (losses) gains, net	(70)	192	(72)	154
Income (loss) before income taxes and noncontrolling interest	496	(2,705)	(215)	(4,966)
Premises
Segment Reporting Information [Line Items]
Net revenue	10,671	8,821	20,001	16,327
Gross profit	$ 5,982	$ 4,818	$ 10,361	$ 8,973
Gross profit margin	56.00%	55.00%	52.00%	55.00%
Identity
Segment Reporting Information [Line Items]
Net revenue	$ 11,566	$ 11,473	$ 21,758	$ 20,495
Gross profit	$ 3,901	$ 3,335	$ 8,226	$ 5,688
Gross profit margin	34.00%	29.00%	38.00%	28.00%