Summary of Significant Accounting Policies - Schedule of Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2017
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life (in years)	3 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life (in years)	10 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life (in years)	3 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life (in years)	5 years
Computer Equipment and Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life (in years)	3 years
Computer Equipment and Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life (in years)	5 years
Buildings [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life (in years)	39 years
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment useful life	Indefinite