Note 10 - Stockholders' Equity - Rollforward of Outstanding Shares (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Shares, beginning of year (in shares)	81,584
Shares, end of period (in shares)	81,584
Common Stock [Member]
Shares, beginning of year (in shares)	5,454,639	5,434,521
Stock-based compensation (in shares)		20,118
Shares, end of period (in shares)	5,454,639	5,454,639
Treasury Stock, Common [Member]
Shares, beginning of year (in shares)	(81,584)	(81,584)
Stock-based compensation (in shares)		0
Shares, end of period (in shares)	(81,584)	(81,584)
Common Stock Outstanding [Member]
Shares, beginning of year (in shares)	5,373,055	5,352,937
Stock-based compensation (in shares)	0	20,118
Shares, end of period (in shares)	5,373,055	5,373,055