Schedule of Adoption of New Revenue Guidance Impact on Condensed Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Net revenue - commercial product sales	$ 3,893	$ 2,163	$ 7,358	$ 5,172
Expenses:
Cost of goods sold	5,095	5,086	9,103	7,635
Net loss	(22,675)	(35,339)	(53,060)	(51,663)
Adjustments | Accounting Standards Update 2014-09
Expenses:
Cost of goods sold	(45)		(1)
Net loss	(178)		202
Balances Without Adoption of Topic 606 | Accounting Standards Update 2014-09
Expenses:
Cost of goods sold	5,050		9,102
Net loss	(22,853)		(52,858)
Net revenue - commercial product sales
Revenues:
Net revenue - commercial product sales	3,753	$ 1,548	7,155	$ 2,745
Net revenue - commercial product sales | Adjustments | Accounting Standards Update 2014-09
Revenues:
Net revenue - commercial product sales	(388)		201
Net revenue - commercial product sales | Balances Without Adoption of Topic 606 | Accounting Standards Update 2014-09
Revenues:
Net revenue - commercial product sales	$ 3,365		$ 7,356