Warrants (Fair Value of Warrants) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Class of Warrant or Right [Line Items]
Fair Value	$ 43		$ 23
Change in Fair Value of common stock warrant liability	(20)	$ 794
2018 January and February Issuance [Member]
Class of Warrant or Right [Line Items]
Fair Value	39		22
2017 May issuance [Member]
Class of Warrant or Right [Line Items]
Fair Value	$ 4		$ 1