Note 7 - Income Taxes - Significant Components of Deferred Tax Liabilities and Assets (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Property and equipment	$ (323,000)	$ (708,000)
Prepaid expenses	(409,000)	(493,000)
ROU asset	(12,000)	(54,000)
Total deferred tax liabilities	(744,000)	(1,255,000)
Net operating loss carryforwards	155,000	139,000
Accruals and allowances	438,000	167,000
Lease liabilities	12,000	61,000
Tax credits	4,000	3,000
Other	140,000	114,000
Capital loss carryover	646,000	646,000
Total deferred tax assets	1,395,000	1,130,000
Valuation allowance	(714,000)	(697,000)
Deferred tax assets net of valuation allowance	681,000	433,000
Net deferred tax liabilities	$ (63,000)	$ (822,000)