Fair Value Measurements (Fair Value, Warrants Measured on Recurring Basis) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair value of warrants at beginning of year			$ 302
Unrealized gain (loss) on fair value adjustment for warrants	$ (4)		289	$ (37)
Fair value of warrants at end of year	591		591
Fair Value, Inputs, Level 3 [Member]
Fair value of warrants at beginning of year	595	$ 237	302	62
Fair value of new warrants, recorded during the year (included as a discount on notes receivable)		12		224
Unrealized gain (loss) on fair value adjustment for warrants	(4)		289	(37)
Fair value of warrants at end of year	$ 591	$ 249	$ 591	$ 249