Basis of Presentation (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Basis of Presentation [Abstract]
Warrants exercised for common stock	$ 3,538	$ 0
Interest paid (net of interest capitalized)	1,161	691
Shares converted to common from preferred stock	0	38,389
Additions to equipment in process included in accounts payable	$ 191	$ 486