Selected Quarterly Financial Data (Unaudited) - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cost of product sales	$ 12,011	$ 14,486	$ 13,997	$ 11,838	$ 3,765	$ 3,783	$ 4,158	$ 2,664	$ 52,332	$ 14,370	$ 5,019
Cost of Sales
Cost of product sales adjustment			$ 1,100
Cost of Sales | Understatement
Cost of product sales										$ 1,700
Cost of Sales | Overstatement
Cost of product sales				$ 600