Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator:
Net loss	$ (590)	$ (605)	$ (1,258)	$ (1,316)
Less: preferred stock dividends	3	3	6	6
Net loss attributable to common stockholders	$ (593)	$ (608)	$ (1,264)	$ (1,322)
Denominator:
Weighted-average number of shares of common stock for basic and diluted net loss per share (in shares)	37,168	35,879	37,168	35,861
Basic and diluted net loss per share (in dollars per share)	$ (0.02)	$ (0.02)	$ (0.03)	$ (0.04)