Note 5 - Restructuring and Other Charges (Details Textual) - USD ($) $ in Thousands				3 Months Ended							12 Months Ended
	Jul. 19, 2021	Jun. 10, 2021	Jul. 19, 2020	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Operating Lease, Impairment Loss							$ 612				$ 0	$ 612
Incremental Sublease Income Above Impairment Charge	$ 350		$ 350
Restructuring Charges, Total				$ 51	$ 197	$ 55	1,078	$ 161	$ 38	$ 8
Severance and Other One-Time Termination Benefits [Member]
Restructuring Charges, Total											120	248
Other Restructuring [Member]
Restructuring Charges, Total											183	173
EMS Segment Restructuring and Facility Consolidation [Member]
Restructuring and Related Costs, Incurred Cost, Total												903
Operating Lease, Impairment Loss											522
EMS Segment Restructuring and Facility Consolidation [Member] | Severance and Other One-Time Termination Benefits [Member]
Restructuring and Related Costs, Incurred Cost, Total											69
Restructuring Charges, Total											0	69
EMS Segment Restructuring and Facility Consolidation [Member] | Other Restructuring [Member]
Restructuring and Related Costs, Incurred Cost, Total											159
Restructuring Charges, Total											183	159
EMS Segment Restructuring and Facility Consolidation [Member] | Facility Closing [Member]
Restructuring and Related Costs, Incurred Cost, Total											675
EMS Segment Restructuring and Facility Consolidation [Member] | Integration of Manufacturing Operations [Member]
Restructuring and Related Costs, Incurred Cost, Total											183
Executive Management Changes [Member]
Restructuring and Related Costs, Incurred Cost, Total											370
Operating Lease, Impairment Loss							$ 90
Restructuring Charges, Total												514
Share-based Payment Arrangement, Reversal of Expense												117
Executive Management Changes [Member] | Severance and Other One-Time Termination Benefits [Member]
Restructuring Charges, Total											120	133
Executive Management Changes [Member] | Other Restructuring [Member]
Restructuring Charges, Total											0	0
Executive Management Changes [Member] | Employee Severance [Member]
Restructuring and Related Costs, Incurred Cost, Total		$ 120									120	133
Executive Management Changes [Member] | Employee Severance [Member] | Restructuring and Other Charges [Member]
Restructuring and Related Costs, Incurred Cost, Total											120
Executive Management Changes [Member] | Legal Fees [Member]
Restructuring and Related Costs, Incurred Cost, Total											159	381
Executive Management Changes [Member] | Facility Size Reduction [Member]
Other Restructuring Costs												99
Stock-based Compensation Expense [Member] | Modification Cost [Member]
Restructuring and Related Costs, Incurred Cost, Total											$ 91
Other Restructuring Actions [Member] | Headcount Reductions and Employee Relocation [Member]
Other Restructuring Costs												46
Other Restructuring Actions [Member] | Employee Relocation [Member]
Other Restructuring Costs												$ 14