Other Accrued Liabilities, Accrued Warranty Costs (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 178	$ 115
Additions charged to warranty expense	91	161
Expiring warranties/claimed satisfied	(19)	(98)
Balance at end of period	$ 250	$ 178
Minimum [Member]
Accrued warranty costs [Abstract]
Standard warranty period	1 year
Offered warranty period	3 years
Maximum [Member]
Accrued warranty costs [Abstract]
Standard warranty period	2 years
Offered warranty period	4 years