Note 9 - Leases - Operating Leases Balance Sheet Information (Details) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022
Noncurrent operating lease liabilities		$ 249	$ 409
Other Noncurrent Assets [Member]
Other noncurrent assets (a)	[1]	517	710
Accrued and Other Current Liabilities [Member]
Accrued and other current liabilities		268	301
Other Noncurrent Liabilities [Member]
Noncurrent operating lease liabilities		249	409
Other Liabilities [Member]
Total liabilities		$ 517	$ 710

[1] Operating lease asset balances at December 31, 2023 and 2022.