Per Share Amounts (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income (loss) attributable to American Shared Hospital Services	$ 43,000	$ 13,000	$ (1,799,000)	$ (1,010,000)
Weighted average common shares for basic earnings per share	5,494,000	5,261,000	5,485,000	4,858,000
Diluted effect of stock options and restricted stock	22,000	43,000	0	0
Weighted average common shares for diluted earnings per share	5,516,000	5,304,000	5,485,000	4,858,000
Basic earnings (loss) per share	$ 0.01	$ 0	$ (0.33)	$ (0.21)
Diluted earnings (loss) per share	$ 0.01	$ 0	$ (0.33)	$ (0.21)