Information Regarding Net Revenue and Gross Profit by Segment (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
Gross profit	$ 8,484	$ 5,861	$ 23,145	$ 17,241
Gross profit margin	42.00%	38.00%	41.00%	39.00%
Operating expenses:
Research and development	$ 1,860	$ 1,597	$ 5,384	$ 4,584
Selling and marketing	3,915	3,448	12,176	10,142
General and administrative	2,641	1,247	7,952	5,119
Restructuring and severance	223	(49)	591	(49)
Total operating expenses	8,639	6,243	26,103	19,796
Loss from operations	(155)	(382)	(2,958)	(2,555)
Non-operating income (expense):
Interest expense, net	(291)	(643)	(1,239)	(1,995)
(Loss) gain on extinguishment of debt, net			(1,369)	977
Foreign currency gains (losses), net	200	(51)	354	(202)
Loss before income taxes and noncontrolling interest	(246)	(1,076)	(5,212)	(3,775)
Premises
Segment Reporting Information [Line Items]
Net revenue	9,364	5,916	25,691	17,058
Gross profit	$ 5,363	$ 3,399	$ 14,336	$ 9,543
Gross profit margin	57.00%	57.00%	56.00%	56.00%
Identity
Segment Reporting Information [Line Items]
Net revenue	$ 3,826	$ 3,421	$ 9,760	$ 10,568
Gross profit	$ 1,337	$ 1,229	$ 3,369	$ 3,667
Gross profit margin	35.00%	36.00%	35.00%	35.00%
Credentials
Segment Reporting Information [Line Items]
Net revenue	$ 6,832	$ 6,095	$ 21,393	$ 16,035
Gross profit	$ 1,784	$ 1,233	$ 5,440	$ 4,026
Gross profit margin	26.00%	20.00%	25.00%	25.00%
All Other
Segment Reporting Information [Line Items]
Net revenue				$ 3
Gross profit				$ 5
Gross profit margin				167.00%