Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Computations of net loss per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Net loss	$ (11,978)	$ (16,755)
Preferred stock dividends	(1,501)	(1,064)
Net Loss Applicable to Common Stockholders	$ (13,479)	$ (17,819)
Weighted average common shares outstanding used to compute net loss per share, basic and diluted	10,840,870	10,838,731
Net loss per share	$ (1.24)	$ (1.64)