Supplemental Balance Sheet Information (Details Narrative) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Other Noncurrent Assets [Member]
Equity securities	$ 4,000	$ 4,000
Income taxes receivable	1,100	2,100
Other assets	300	300
Other Noncurrent Assets [Member] | NXSN Acquisition Corp [Member]
Stock issued pursuant to acquisitions	700
Other Current Liabilities [Member]
Pension liabilities	23,000	24,300
Other liabilities	$ 700	$ 900