Property and Equipment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 11,310		$ 11,310		$ 9,153
Less: accumulated depreciation	(2,011)		(2,011)		(1,105)
Property and equipment, net	9,299		9,299		8,048
Depreciation expense	300	$ 200	900	$ 600
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,775		$ 1,775		$ 1,463
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)			7 years		7 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)			20 years		20 years
Machinery & equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,105		$ 7,105		$ 6,066
Machinery & equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)			1 year		1 year
Machinery & equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)			12 years		12 years
Furniture
Property, Plant and Equipment [Line Items]
Property and equipment, gross	967		$ 967		$ 843
Furniture | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)			1 year		1 year
Furniture | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)			12 years		12 years
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,463		$ 1,463		$ 781