Other Financial Statement Data (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Product Liability Contingency [Line Items]
Depreciation expense	$ 1,300,000	$ 1,300,000
Amortization expense, 2019	150,000
Amortization expense, 2020	119,000
Amortization expense, 2021	44,000
Amortization expense, 2022	9,000
Amortization expense, 2023	$ 9,000
Minimum [Member]
Product Liability Contingency [Line Items]
Warranty period (in years)	1 year
Maximum [Member]
Product Liability Contingency [Line Items]
Warranty period (in years)	3 years