Summary of Other Current Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Prepaid Expense And Other Assets Current [Abstract]
Manufacturing-related deposits	$ 14,450	$ 30,668
Prepaid expenses	4,382	2,797
Other	634	1,571
Total other current assets	$ 19,466	$ 35,036