Note 5 - Leases (Details Textual) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 02, 2019 USD ($)	Jun. 02, 2019 USD ($)	Dec. 31, 2018 ft²
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 173	$ 173
Lessee, Operating Lease, Liability, Payments, Due Year Two	61	$ 61
Operating Lease, Expense	97
Operating Lease, Payments	$ 95
Operating Lease, Weighted Average Remaining Lease Term	6 years	6 years
Additional Manufacturing Facility [Member]
Area of Land | ft²			90,000
Construction in Progress Expenditures Incurred but Not yet Paid		$ 20,000
Purchase Obligation, Total	$ 2,173	2,173
Accrued Liabilities [Member]
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	588	588
Lessee, Operating Lease, Liability, Payments, Due Year Two	$ 463	$ 463
Minimum [Member]
Lessee, Operating Lease, Renewal Term	1 year	1 year
Maximum [Member]
Lessee, Operating Lease, Renewal Term	10 years	10 years