Property and Equipment - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Total cost	$ 77,778	$ 67,649
Less: Accumulated depreciation	(39,885)	(36,477)
Property and equipment, net	37,893	31,172
Land
Property, Plant and Equipment [Line Items]
Total cost	2,900	2,900
Building and leasehold improvements
Property, Plant and Equipment [Line Items]
Total cost	$ 19,578	18,383
Building and leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Building and leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	39 years
Production equipment
Property, Plant and Equipment [Line Items]
Total cost	$ 19,817	19,075
Production equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Production equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Computers, equipment and software
Property, Plant and Equipment [Line Items]
Total cost	$ 8,392	6,780
Computers, equipment and software | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Computers, equipment and software | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Total cost	$ 6,529	5,262
Furniture and office equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Furniture and office equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Life	7 years
Vehicles
Property, Plant and Equipment [Line Items]
Estimated Useful Life	5 years
Total cost	$ 1,385	1,057
Website development costs
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Total cost	$ 687	687
Capitalized internal-use software development costs
Property, Plant and Equipment [Line Items]
Estimated Useful Life	3 years
Total cost	$ 3,670	3,695
Construction-in-process
Property, Plant and Equipment [Line Items]
Total cost	$ 14,820	$ 9,810