Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share [Abstract]
Net loss	$ (6,795)	$ (11,667)
Weighted average common shares outstanding (in shares)	86,783	83,462
Net loss per share, basic and diluted (in dollars per share)	$ (0.08)	$ (0.14)