Business Combination - Schedule of Estimated Fair Values of Assets acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	Oct. 16, 2017	Dec. 31, 2017	Dec. 31, 2016	Sep. 30, 2017
Business Acquisition [Line Items]
Goodwill		$ 10,012		$ 3,014
Customer relationships
Business Acquisition [Line Items]
Amortization Period		3 years 9 months 18 days		6 years
ICAR Vision Systems, S.L.
Business Acquisition [Line Items]
Current assets	$ 2,036
Property, plant, and equipment	83
Intangible assets	6,407
Goodwill	6,852
Other non-current assets	87
Current liabilities	(1,568)
Other non-current liabilities	(2,430)
Net assets acquired	11,467
Finite-lived intangible assets acquired	6,407
Pro forma revenue		$ 13,043	$ 10,240
Pro forma net loss		$ (5,110)	$ (780)
ICAR Vision Systems, S.L. | Completed technologies
Business Acquisition [Line Items]
Amortization Period		5 years
Finite-lived intangible assets acquired	4,956
ICAR Vision Systems, S.L. | Customer relationships
Business Acquisition [Line Items]
Amortization Period		2 years
Finite-lived intangible assets acquired	1,298
ICAR Vision Systems, S.L. | Trade names
Business Acquisition [Line Items]
Amortization Period		3 years
Finite-lived intangible assets acquired	$ 153