Accounts Receivable (Allowance For Doubtful Accounts Receivable) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance			$ (390)	$ (635)	$ (635)
Provision for bad debts on trade receivables			19		72
Other allowances			(20)		58
Accounts receivable write offs	$ 32	$ 39	32	$ 65	115
Ending balance	$ (359)		$ (359)		$ (390)