Property, plant and equipment, net - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 258,502	$ 215,455
Construction In Progress North Carolina Manufacturing Facility [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	27,300	12,900
60 Binney Street [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	167,600	164,400
Construction cost incurred by landlord	156,000	$ 156,000
North Carolina Manufacturing Facility [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 12,200