Warrants (Fair Value of Warrants) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Class of Warrant or Right [Line Items]
Fair Value	$ 3,327		$ 3,327		$ 23
Change in Fair Value of common stock warrant liability	(1,803)	$ 120	(3,304)	$ 1,450
2018 January and February Issuance [Member]
Class of Warrant or Right [Line Items]
Fair Value	2,603		2,603		22
2017 May issuance [Member]
Class of Warrant or Right [Line Items]
Fair Value	$ 724		$ 724		$ 1