Segment Reporting - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Segment	Dec. 31, 2017 USD ($)	Dec. 31, 2016
Segment Reporting Information [Line Items]
Number of operating business segment | Segment	1
Property, plant and equipment, net	$ 48,851	$ 47,463
United States [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 42,900	$ 41,700
Percentage of net book value of property and equipment	88.00%	88.00%
India [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 5,900	$ 5,800
Percentage of net book value of property and equipment	12.00%	12.00%
Revenue [Member] | BMS | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage revenue from customers	89.00%
Revenue [Member] | Eli Lilly & Co [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage revenue from customers		42.00%
Revenue [Member] | UCB [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage revenue from customers		12.00%	21.00%
Revenue [Member] | AstraZeneca [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage revenue from customers			29.00%
Revenue [Member] | Ophthotech Corporation [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage revenue from customers			19.00%
Revenue [Member] | Roche [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Percentage revenue from customers			11.00%