Note 6 - Per Share Amounts - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net (loss) income attributable to American Shared Hospital Services	$ (207,000)	$ 118,000	$ 3,514,000	$ 195,000
Weighted average common shares for basic (loss) earnings per share (in shares)	6,482,000	6,366,000	6,482,000	6,336,000
Dilutive effect of stock options and restricted stock awards (in shares)	0	66,000	38,000	70,000
Weighted average common shares for diluted (loss) earnings per share (in shares)	6,482,000	6,432,000	6,520,000	6,406,000
Basic (loss) earnings per share (in dollars per share)	$ (0.03)	$ 0.02	$ 0.54	$ 0.03
Diluted (loss) earnings per share (in dollars per share)	$ (0.03)	$ 0.02	$ 0.54	$ 0.03