Note 6 - Per Share Amounts - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net income attributable to American Shared Hospital Services	$ 118,000	$ 316,000	$ 195,000	$ 1,082,000
Weighted average common shares for basic earnings per share (in shares)	6,366,000	6,234,000	6,336,000	6,223,000
Dilutive effect of stock options and restricted stock awards (in shares)	66,000	39,000	70,000	38,000
Weighted average common shares for diluted earnings per share (in shares)	6,432,000	6,273,000	6,406,000	6,261,000
Basic earnings per share (in dollars per share)	$ 0.02	$ 0.05	$ 0.03	$ 0.17
Diluted earnings per share (in dollars per share)	$ 0.02	$ 0.05	$ 0.03	$ 0.17