Note 8 - Stock-based Compensation Expense - Stock Compensation Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement, Expense	$ 399,000
Awards issued and vested (in shares)	135,000
Stock-based compensation expense	$ 399,000
Management Bonus Program [Member]
Share-Based Payment Arrangement, Expense	$ 92,000
Awards issued and vested (in shares)	11,000
Stock-based compensation expense	$ 92,000
Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Expense	$ 10,000	$ 2,000
Awards issued and vested (in shares)	3,000
Stock-based compensation expense	$ 10,000	$ 2,000
Restricted Stock Units (RSUs) [Member]
Awards issued and vested (in shares)	132,000	168,000
Restricted Stock Units (RSUs) [Member] | Board Member [Member]
Share-Based Payment Arrangement, Expense	$ 3,000
Stock-based compensation expense	3,000
Restricted Stock Units (RSUs) [Member] | Chief Executive Officer [Member]
Share-Based Payment Arrangement, Expense	$ 288,000
Awards issued and vested (in shares)	120,000
Stock-based compensation expense	$ 288,000
Restricted Stock Units (RSUs) [Member] | Non Employee Directors and Corporate Secretary [Member]
Share-Based Payment Arrangement, Expense	$ 6,000
Awards issued and vested (in shares)	1,000
Stock-based compensation expense	$ 6,000