Supplemental Balance Sheet Information (Details Narrative) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
NXSN Acquisition Corp. [Member]
Other assets	$ 200
Other Assets [Member]
Investments in Equity securities	4,000
Income taxes receivable	1,100
Other Assets [Member] | NXSN Acquisition Corp. [Member]
Stock issued pursuant to acquisitions	700
Other Current Liabilities [Member]
Pension minimum contributions	1,900	$ 1,900
Levy accruals	0	300
Accrued payroll	100	200
Other Liabilities [Member]
Pension liabilities	$ 14,400	$ 24,300