Segments and Geographic Information - Schedule of Revenue by Customer (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Entity Wide Revenue Major Customer [Line Items]
Total revenues	100.00%	100.00%	100.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Merck KGaA [Member]
Entity Wide Revenue Major Customer [Line Items]
Total revenues	66.00%	86.00%	74.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Allergan [Member]
Entity Wide Revenue Major Customer [Line Items]
Total revenues	34.00%	14.00%	16.00%
Customer Concentration Risk [Member] | Sales Revenue, Net [Member] | Lil Drug Store [Member]
Entity Wide Revenue Major Customer [Line Items]
Total revenues			10.00%