Earnings Per Share Applicable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Net loss	$ (3,711)	$ (7,755)	$ (9,613)	$ (16,092)
Basic and diluted loss per common share	$ (0.06)	$ (0.14)	$ (0.16)	$ (0.29)
Basic and diluted weighted average common shares outstanding	60,906	55,539	60,344	55,433
Stock Option [Member]
Potentially dilutive securities (in thousands)	11,457,000	10,174,000	11,457,000	10,174,000
Warrant [Member]
Potentially dilutive securities (in thousands)	0	140,000	0	140,000
Convertible notes [Member]
Potentially dilutive securities (in thousands)	0	2,192,000	0	2,192,000