Note 3 - Revision of Previously Issued Financial Statements for Correction of Immaterial Errors - Schedule of Adjustments to Prepaid Expenses and Other Current Assets and Other Noncurrent Assets (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Assets, Current [Abstract]
Cash and cash equivalents	$ 12,383,000	$ 10,495,000
Prepaid expenses and other current assets	2,350,000	1,011,000
Total current assets	14,733,000	11,506,000
Restricted cash	26,000	26,000
Right-of-use asset	300,000	109,000
Other noncurrent assets	694,000	868,000
Property and equipment, net	10,000	3,000
Total assets	$ 15,763,000	12,512,000
Previously Reported [Member]
Assets, Current [Abstract]
Cash and cash equivalents		10,495,000
Prepaid expenses and other current assets		1,879,000
Total current assets		12,374,000
Restricted cash		26,000
Right-of-use asset		109,000
Other noncurrent assets		0
Property and equipment, net		3,000
Total assets		12,512,000
Revision of Prior Period, Adjustment [Member]
Assets, Current [Abstract]
Cash and cash equivalents		0
Prepaid expenses and other current assets		(868,000)
Total current assets		(868,000)
Restricted cash		0
Right-of-use asset		0
Other noncurrent assets		868,000
Property and equipment, net		0
Total assets		$ 0