Note 10 - Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Operating lease right-of-use assets	$ 975	$ 1,308
Property and equipment at cost	45,599	42,705
Less accumulated amortization	(33,208)	(30,979)
Property and equipment under finance lease, net	12,391	11,726
Current obligations of finance leases	470	493
Noncurrent obligations of finance leases	348	778
Total finance lease liabilities	$ 818	$ 1,271
Operating leases (Year)	2 years 9 months 18 days	3 years 8 months 4 days
Finance leases (Year)	1 year 11 months 4 days	2 years 8 months 8 days
Operating leases	3.85%	4.40%
Finance leases	3.42%	3.38%
Other Current Liabilities [Member]
Current operating lease liabilities	$ 493	$ 461
Other Noncurrent Liabilities [Member]
Operating lease obligations, net of current portion	820	896
Other Current Liabilities and Other Noncurrent Liabilities [Member]
Total operating lease liabilities	1,313	1,357
Furniture and Equipment Held under Finance Leases [Member]
Property and equipment at cost	1,042	1,014
Computer Equipment Held under Finance Leases [Member]
Property and equipment at cost	659	662
Computer Software Held under Finance Leases [Member]
Property and equipment at cost	207	207
Assets Held under Finance Leases [Member]
Property and equipment at cost	1,908	1,883
Less accumulated amortization	(1,074)	(605)
Property and equipment under finance lease, net	$ 834	$ 1,278