Net Loss Per Share - Computation of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Net loss	$ (9,321)	$ (25,562)
Weighted average shares - basic and diluted (shares)	65,597,261	64,880,677
Net loss per share - basic and diluted ($ per share)	$ (0.14)	$ (0.39)