Description of Business and Basis of Presentation (Net Income (Loss) per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator
Net loss	$ (10,399)	$ (6,848)
Denominator
Weighted-average common shares outstanding	32,197	31,650
Net loss per share
Basic and diluted (in dollars per share)	$ (0.32)	$ (0.22)