Warrants (Fair Value of Warrants) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Class of Warrant or Right [Line Items]
Fair Value at December 31,	$ 23	$ 1,497
Change in Fair Value of common stock warrant liability	1,474	2,194
2018 January and February Issuance [Member]
Class of Warrant or Right [Line Items]
Fair Value at December 31,	22	1,342
2017 May issuance [Member]
Class of Warrant or Right [Line Items]
Fair Value at December 31,	$ 1	$ 155