License and Development Agreements - Meda License, Development and Supply Agreements - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Revenue Recognition, Milestone Method [Line Items]
Contract revenues	$ 2,500,000	$ 20,000,000	$ 2,500,000
U.S. [Member]
Revenue Recognition, Milestone Method [Line Items]
Contract revenues				$ 0
U.S. [Member] | Milestones [Member]
Revenue Recognition, Milestone Method [Line Items]
Contract revenues					$ 1,000,000