Liquidity - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Liquidity And Managements Plans [Abstract]
Cash	$ 32,019	$ 83,560	$ 70,472	$ 23,176
Cash used	(51,541)	13,088	47,296
Stockholders' (deficit) equity	$ (17,665)	$ 31,696	$ 54,396	$ (812)