Net 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
Numerator:
Net loss available for common shareholders - basic and diluted	$ (3,513)	$ (3,355)	$ (10,244)	$ (14,774)
Denominator:
Weighted-average shares outstanding - basic and diluted	47,216	43,858	46,292	40,605
Net loss per share - basic and diluted	$ (0.07)	$ (0.08)	$ (0.22)	$ (0.36)