Nature of the Business and Summary of Significant Accounting Policies - Schedules of Concentration of Risk by Risk Factor - Gross Sales Revenue (Detail) - Sales Revenue, Net [Member] - Customer Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Baxalta [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross revenue	60.00%	93.00%	10.00%
Sanofi [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross revenue			90.00%
Amerisource Bergen Corporation [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross revenue	15.00%
Amerisource Bergen Corporation [Member] | Maximum [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross revenue		10.00%
McKesson Corporation [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross revenue	16.00%
McKesson Corporation [Member] | Maximum [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross revenue		10.00%