Goodwill and Intangible Assets, Net - Schedule of Goodwill and Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Intangible Assets By Major Class [Line Items]
Intangible assets, Accumulated Amortization	$ (2,623)	$ (2,045)
Goodwill	3,605	3,605
Goodwill and Intangible assets, Gross Carrying Value	10,205	13,005
Goodwill and Intangible assets, Net Carrying Value	7,582	10,960
IPR&D [Member]
Intangible Assets By Major Class [Line Items]
Indefinite-lived intangible asset		2,800
Nano Carrier Technology [Member]
Intangible Assets By Major Class [Line Items]
Intangible assets, Gross Carrying Value	3,200	3,200
Intangible assets, Accumulated Amortization	(2,315)	(1,995)
Intangible assets, Net Carrying Value	885	1,205
ONIVYDE [Member]
Intangible Assets By Major Class [Line Items]
Intangible assets, Gross Carrying Value	3,400	3,400
Intangible assets, Accumulated Amortization	(308)	(50)
Intangible assets, Net Carrying Value	$ 3,092	$ 3,350