Per Share Amounts (Details) - USD ($)	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income attributable to American Shared Hospital Services	$ 51,000	$ 128,000
Weighted average common shares for basic earnings per share	5,541,000	5,477,000
Diluted effect of stock options and restricted stock	0	49,000
Weighted average common shares for diluted earnings per share	5,541,000	5,526,000
Basic earnings per share	$ 0.01	$ 0.02
Diluted earnings per share	$ 0.01	$ 0.02

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