Inventories (Schedule of Inventory Reserve) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Inventory Valuation Reserves [Roll Forward]
Balance, beginning of year	$ 368	$ 50	$ 50
Charged to costs and expenses	2,418	388	0
Deductions	(669)	(70)	0
Balance, end of the year	$ 2,117	$ 368	$ 50