Note 8 - Income Taxes (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	December 31,
	2022			2021
Deferred tax assets:
Net operating losses	$	69,537		$	64,418
Fixed asset basis difference		4,599			4,566
Contributions carryover		48			38
Deferred compensation		695			497
Accrued liabilities and other		358			333
Total deferred tax assets		75,237			69,852
Valuation allowance for deferred tax assets		(75,237	)		(69,852	)
Net deferred tax asset	$	-		$	-

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	2022			2021
Expected federal income tax benefit at 21%	$	(5,205	)	$	(6,560	)
Increase (decrease) in valuation allowance		3,906			(8,530	)
State income tax		7			10
Expiring carryforwards		577			14,260
Non-deductible expenses and other		722			830
Income tax expense	$	7		$	10