Nature of the Business and Summary of Significant Accounting Policies - Schedules of Concentration of Risk by Risk Factor - Gross Accounts Receivable (Detail) - Accounts Receivable [Member] - Credit Concentration Risk [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Baxalta [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross accounts receivable	20.00%	29.00%
Amerisource Bergen Corporation [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross accounts receivable	25.00%	29.00%
McKesson Corporation [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross accounts receivable	32.00%	25.00%
Cardinal Health Inc [Member]
Concentration Risk [Line Items]
Customer's accounted for more than 10% percent gross accounts receivable	21.00%	16.00%