Quarterly Results of Operation (Unaudited) - Summary of Unaudited Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Total revenues	$ 53	$ 1,466							$ 1,519		$ 401
Cost of goods sold	38	1,031							1,069
Amortization of intangible assets	1,655	1,709	$ 1,786	$ 1,817	$ 1,596	$ 338	$ 126	$ 125	6,967	$ 2,185	503
Goodwill impairment			61,784						61,784	0
Restructuring and other charges	(21)		3,085						3,064
Inventory write-down related to restructuring			2,565						2,565
Acquisition related costs					228	4,003			0	4,231
Other operating expenses	12,769	12,278	11,509	13,163	12,076	9,223	8,942	9,714	49,719	39,955
Interest expense, net	420	462	394	578	604	436	280	281	1,854	1,601	1,043
Loss before income taxes	(14,808)	(14,014)	(81,123)	(15,558)	(14,504)	(14,000)	(9,348)	(10,120)	(125,503)	(47,972)	(37,652)
Income tax benefit	816	1,070	992	2,645	925	99			5,523	1,024
Net loss	$ (13,992)	$ (12,944)	$ (80,131)	$ (12,913)	$ (13,579)	$ (13,901)	$ (9,348)	$ (10,120)	$ (119,980)	$ (46,948)	$ (37,652)
Net loss per share - basic and diluted	$ (0.12)	$ (0.11)	$ (0.70)	$ (0.12)	$ (0.13)	$ (0.16)	$ (0.14)	$ (0.16)	$ (1.07)	$ (0.59)	$ (0.64)