Fair Value Measurements (Fair Value, Warrants Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair value of warrants at beginning of period	$ 229
Unrealized gain (loss) on fair value adjustment for warrants	42	$ (3)
Fair value of warrants at end of period	271	229
Level 3 Estimated Fair Value [Member]
Fair value of warrants at beginning of period	229	232
Unrealized gain (loss) on fair value adjustment for warrants	42	(3)
Fair value of warrants at end of period	$ 271	$ 229