Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 10, 2022
Document Information [Line Items]
Entity Central Index Key	0000744825
Entity Registrant Name	AMERICAN SHARED HOSPITAL SERVICES
Amendment Flag	true
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2022
Document Type	10-Q/A
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	001-08789
Entity Incorporation, State or Country Code	CA
Entity Tax Identification Number	94-2918118
Entity Address, Address Line One	601 Montgomery Street
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94111-2619
City Area Code	415
Local Phone Number	788-5300
Title of 12(b) Security	American Shared Hospital Services Common Stock, No Par Value
Trading Symbol	AMS
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Amendment Description	The purpose of this Amendment No. 1 to the Company’s Quarterly Report on Form 10-Q for the period ended June 30, 2022, filed with the Securities and Exchange Commission on August 15, 2022 (the “Original Filing”), is solely to correct signature dates on Exhibits 31.1, 31.2, and 32.   This Amendment is limited in scope to the items identified above. This Amendment does not reflect events occurring after the filing of the Original Filing and no revisions are being made to the Company’s financial statements or disclosures pursuant to this Amendment.
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		6,112,000