Property and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 16,508		$ 14,602
Less: accumulated depreciation	(2,771)		(2,402)
Property and equipment, net	13,737		12,200
Depreciation expense	400	$ 300
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,015		2,976
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	7 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	20 years
Machinery & equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 7,799		7,853
Machinery & equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Machinery & equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	12 years
Furniture
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,707		1,698
Furniture | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Furniture | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	12 years
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,987		$ 2,075