Loss Per Share (Calculation of Loss Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net loss	$ (6,605)	$ (7,551)	$ (22,921)	$ (25,088)
Weighted average common shares outstanding	24,318	23,347	24,291	23,162
Basic and diluted loss per share	$ (0.27)	$ (0.32)	$ (0.94)	$ (1.08)