Note 10 - Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating lease right-of-use assets	$ 556	$ 975
Property and equipment at cost	50,756	45,599
Less accumulated depreciation and amortization	33,508	33,208
Property and equipment under finance lease, net	$ 17,248	$ 12,391
Operating leases (Year)	1 year 11 months 12 days	2 years 9 months 18 days
Finance leases (Year)	1 year 1 month 24 days	1 year 11 months 4 days
Operating leases	3.97%	3.85%
Finance leases	3.54%	3.42%
Other Current Liabilities [Member]
Current portion, operating leases	$ 522	$ 493
Current portion, finance leases	311
Other Noncurrent Liabilities [Member]
Operating lease obligations, net of current portion	333	820
Noncurrent obligations of finance leases	39
Other Current Liabilities and Other Noncurrent Liabilities [Member]
Total operating lease liabilities	855	1,313
Total finance lease liabilities	350
Property and Equipment [Member]
Current portion, finance leases	311	470
Noncurrent obligations of finance leases	39	348
Total finance lease liabilities	350	818
Furniture and Equipment Held under Finance Leases [Member]
Property and equipment at cost	1,042	1,042
Computer Equipment Held under Finance Leases [Member]
Property and equipment at cost	659	659
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	1,908
Less accumulated depreciation and amortization	1,537	1,074
Property and equipment under finance lease, net	$ 371	$ 834