Payment Obligation in Connection with Hirsch Acquisition (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
2019 (remaining nine months)	$ 12,998
2020	872
Total	13,870
Less: Current portion - payment obligation	(1,050)	$ (1,025)
Long-term payment obligation	1,569	$ 1,860
Hirsch Electronics
Related Party Transaction [Line Items]
2019 (remaining nine months)	956
2020	1,408
2021	363
Present value discount factor	(108)
Total	2,619
Less: Current portion - payment obligation	(1,050)
Long-term payment obligation	$ 1,569