License Agreements and Acquired Product Rights - Additional Information (Detail) $ in Millions		1 Months Ended				3 Months Ended
	Oct. 07, 2010 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2018 CAD ($)	Oct. 31, 2017 CAD ($)	Aug. 31, 2017 CAD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Jul. 12, 2017 CAD ($)
TTY License and Supply Agreement [Member]
Indefinite-lived Intangible Assets [Line Items]
Upfront payment	$ 0.3
Term of the agreement						15 years
Milestone payment received						$ 0.4	$ 0.0
TTY License and Supply Agreement [Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Milestone payments	$ 1.3
Collaborative Arrangement, Product [Member] | Purdue Pharma [Member] | BELBUCA [Member]
Indefinite-lived Intangible Assets [Line Items]
Upfront and potential milestones payable								$ 1,500,000
Milestone based payments received		$ 0.8	$ 1,000,000	$ 1,000,000	$ 500,000
Collaborative Arrangement, Product [Member] | Purdue Pharma [Member] | BELBUCA [Member] | Maximum [Member]
Indefinite-lived Intangible Assets [Line Items]
Upfront and potential milestones payable								$ 4,500,000