Goodwill and Intangible Assets, Net - Schedule of Changes in the Carrying Value of Goodwill, IPR&D and Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Intangible Assets By Major Class [Line Items]
Intangible asset	$ 7,355	$ 7,725
Goodwill	3,605	3,605	$ 3,605
Core Nano Carrier Technology [Member]
Intangible Assets By Major Class [Line Items]
Intangible asset	1,205	1,525	1,845
Amortization	(320)	(320)
ONIVYDE [Member]
Intangible Assets By Major Class [Line Items]
Intangible asset	3,350
Amortization	(50)
Reclassification of IPR&D to definite-lived intangible assets	3,400
IPR&D Program [Member]
Intangible Assets By Major Class [Line Items]
IPR&D	2,800	$ 6,200	$ 6,200
Reclassification of IPR&D to definite-lived intangible assets	$ (3,400)