Note 10 - Retirement Plans (Details Textual)	3 Months Ended		9 Months Ended
	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 64,000	$ 57,900	$ 230,200	$ 206,300
Other Postretirement Benefits Cost (Reversal of Cost)	2,100	2,000	6,400	5,900
Employee benefits	$ 573,000	549,000	$ 1,486,000	1,597,000
Supplemental Employee Retirement Plan [Member]
Number of Employees Participating in Plan	4		4
Employee benefits	$ 58,500	$ 66,000	$ 187,900	$ 198,000
Profit Sharing Plan [Member]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match			4.00%
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage			100.00%