Fair Value Measurements (Fair Value, Warrants Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair value of warrants at beginning of period	$ 731
Unrealized loss on fair value adjustment for warrants	(29)	$ (4)
Fair value of warrants at end of period	702
Fair Value, Inputs, Level 3 [Member]
Fair value of warrants at beginning of period	731	302
Unrealized loss on fair value adjustment for warrants	(29)	(4)
Fair value of warrants at end of period	$ 702	$ 298