Note 8 - Stock-based Compensation Expense - Stock Compensation Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-Based Payment Arrangement, Expense	$ 389,000
Awards issued and vested (in shares)	116,000
Stock-based compensation expense	$ 389,000
Management Bonus Program [Member]
Awards issued and vested (in shares)	26,000
Share-Based Payment Arrangement, Option [Member]
Share-Based Payment Arrangement, Expense	$ 34,000	$ 10,000
Stock-based compensation expense	$ 34,000	$ 10,000
Restricted Stock Units (RSUs) [Member]
Awards issued and vested (in shares)	119,000	132,000
Restricted Stock Units (RSUs) [Member] | Board Member [Member]
Share-Based Payment Arrangement, Expense	$ 4,000
Stock-based compensation expense	4,000
Restricted Stock Units (RSUs) [Member] | Chief Executive Officer [Member]
Share-Based Payment Arrangement, Expense	$ 351,000
Awards issued and vested (in shares)	90,000
Stock-based compensation expense	$ 351,000