Liquidity and Management's Plans - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Liquidity And Managements Plans [Abstract]
Cash and cash equivalents	$ 44,682	$ 54,429	$ 83,560	$ 70,472
Cash used	(38,878)	$ (16,043)
Stockholders' (deficit) equity	$ (5,103)		$ 31,696