Summary of Significant Accounting Policies (Net Loss Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss available for common shareholders	$ (3,570)	$ (2,826)	$ (2,304)	$ (4,934)	$ (3,284)	$ (6,141)	$ (8,990)	$ (8,068)	$ (13,634)	$ (26,483)
Dilutive incremental share effect from:
Weighted-average common shares outstanding									139,829,000	111,297,000
Net loss per share - basic and diluted	$ (0.02)	$ (0.02)	$ (0.02)	$ (0.04)	$ (0.03)	$ (0.05)	$ (0.08)	$ (0.08)	$ (0.10)	$ (0.24)