Net Loss Per Share - Computation of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net loss	$ (3,385)	$ (3,129)	$ (875)	$ (598)	$ (6,514)	$ (1,473)
Less: preferred stock dividends	(4)		(4)		(8)	(19)
Net loss attributable to common stockholders	$ (3,389)		$ (879)		$ (6,522)	$ (1,492)
Denominator:
Weighted-average number of shares of common stock for diluted net loss per share (in shares)	5,240		5,163		5,222	5,134
Basic and diluted net loss per share (in dollars per share)	$ (0.65)		$ (0.17)		$ (1.25)	$ (0.29)