Development, Commercialization and Supply Agreement - Additional Information (Detail)	1 Months Ended			12 Months Ended
	Sep. 30, 2017 USD ($)	Mar. 31, 2016 USD ($)	Feb. 28, 2015 USD ($)	Dec. 31, 2017 USD ($) Item	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
License And Collaboration Agreements [Line Items]
Licensing revenue				$ 1,279,000	$ 1,118,000	$ 769,000
Deferred revenue				$ 18,800,000	$ 15,100,000
Eddingpharm
License And Collaboration Agreements [Line Items]
Non-refundable up-front received			$ 15,000,000
Licensing agreement term			16 years
Number of indications of the regulatory milestone events relating to the submission and approval | Item				3
Amounts to be received upon achievement of the regulatory milestone events				$ 33,000,000
Sales-based milestone event payment				120,000,000
Eddingpharm | Maximum
License And Collaboration Agreements [Line Items]
Additional upfront payment eligible to receive based on development, regulatory and sales Milestone				153,000,000
Amounts to be received upon achievement of the regulatory milestone events				15,000,000
Sales-based milestone event payment				50,000,000
Eddingpharm | Minimum
License And Collaboration Agreements [Line Items]
Amounts to be received upon achievement of the regulatory milestone events				1,000,000
Sales-based milestone event payment				5,000,000
Eddingpharm | Clinical Trial Application
License And Collaboration Agreements [Line Items]
Licensing agreement term		4 years
Non-refundable milestone payment		$ 1,000,000
Biologix FZCo
License And Collaboration Agreements [Line Items]
Revenue recognition period of non-refundable up-front payment		10 years
HLS
License And Collaboration Agreements [Line Items]
Non-refundable up-front received	$ 5,000,000
Licensing agreement term	12 years 6 months
Non-refundable up-front received period	6 months
HLS | Maximum
License And Collaboration Agreements [Line Items]
Additional upfront payment eligible to receive based on development, regulatory and sales Milestone				$ 60,000,000