Document And Entity Information The Credit Agreement, First Loan and Second Loan Facility [Member] Represents credit agreement, first loan and second loan facility. Statistical Measurement [Axis] Note To Financial Statement Details Textual Significant Accounting Policies Note 1 - Basis of Presentation Income tax expense Income tax expense (benefit) ecd_NonRule10b51ArrTrmntdFlag Non-Rule 10b5-1 Arrangement Terminated [Flag] Note 2 - Property and Equipment ecd_NonRule10b51ArrAdoptedFlag Non-Rule 10b5-1 Arrangement Adopted [Flag] Note 3 - Long-Term Debt Financing Trading Arrangements, by Individual [Table] Note 4 - Other Accrued Liabilities Material Terms of Trading Arrangement [Text Block] Note 5 - Leases Note 6 - Per Share Amounts Note 9 - Related Party Transactions and Balances Note 1 - Basis of Presentation - Revenues Allocations to Reportable Segments (Details) Note 1 - Basis of Presentation - Allocations to Reportable Segments (Details) Minimum [Member] Note 1 - Basis of Presentation - Profit (Loss) Allocations to Reportable Segments (Details) Note 1 - Basis of Presentation - Assets Allocations to Reportable Segments (Details) Statistical Measurement [Domain] Note 1 - Basis of Presentation - Revenues Allocated by Geographic Area (Details) Maximum [Member] Note 2 - Property and Equipment - Summary of Property and Equipment (Details) Note 2 - Property and Equipment - Depreciation (Details) Note 3 - Long-Term Debt Financing - Long-term Debt Maturities (Details) Note 4 - Other Accrued Liabilities - Other Accrued Liabilities (Details) us-gaap_IncreaseDecreaseInAccountsReceivable Receivables Note 5 - Leases - Summary of Maturities of Lessee Operating Lease Liabilities (Details) Note 5 - Leases - Lease Cost and Information (Details) Accounts payable and accrued liabilities us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities Note 6 - Per Share Amounts - Computation of Basic and Diluted Earnings Per Share (Details) Note 9 - Related Party Transactions and Balances - Schedule of Related Party Transactions (Details) Notes To Financial Statements us-gaap_CostDepreciationAmortizationAndDepletion Depreciation and amortization Notes To Financial Statements [Abstract] ams_LongtermInstallServiceAndPurchaseCommitmentAmount Long-term Install Service and Purchase Commitment, Amount The minimum amount the entity agreed to spend under the long-term install service and purchase commitment. Leksell Gamma Knife Icon Systems and Linear Accelerator System [Member] Represents Leksell Gamma Knife Icon Systems and Linear Accelerator System. ams_LongtermCommitmentCashOnHandToFund Long-term Commitment, Cash on Hand to Fund The amount of cash on hand to fund long-term commitment. PBRT Services [Member] Represents PBRT service. us-gaap_LesseeOperatingLeaseRemainingLeaseTerm Lessee, Operating Lease, Remaining Lease Term (Year) us-gaap_LesseeOperatingLeaseDiscountRate Lessee, Operating Lease, Discount Rate Land Land and Parking Spaces for Gamma Knife Facility in Guayaquil, Ecuador [Member] Represents land and parking spaces for Gamma knife facility in Guayaquil, Ecuador. Condominium Space for Gamma Knife Facility in Guayaquil, Ecuador [Member] Represents condominium space for Gamma knife facility in Guayaquil, Ecuador. ams_UnrecognizedTaxBenefitsDecreaseResultingFromForeignTaxes Unrecognized Tax Benefits, Decrease Resulting from Foreign Taxes Amount of decrease in unrecognized tax benefits resulting from foreign taxes. Award Type [Axis] Adjustments to reconcile net loss to net cash from operating activities: Segment Reporting, Reconciliation of Profit (Loss) by Segment to Consolidated [Table Text Block] us-gaap_Liabilities Total liabilities Segment Reporting, Reconciliation of Revenue by Segment to Consolidated [Table Text Block] Segment Reporting, Reconciliation of Other Item by Segment to Consolidated [Table Text Block] Segment Reporting, Reconciliation of Asset by Segment to Consolidated [Table Text Block] us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and shareholders' equity ams_UnfavorableLeasePosition Accretion of unfavorable lease position Represents the unfavorable lease position reported as an adjustment to reconcile net income to net cash from operating activities. us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Prepaid expenses and other assets Stock-based compensation expense Selling and administrative expense Lessee, Lease, Description [Table] Lease Contractual Term [Axis] Lease Contractual Term [Domain] Changes in operating assets and liabilities: Detail of cash, cash equivalents and restricted cash at end of period us-gaap_RestrictedCash Restricted cash us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect Net change in cash, cash equivalents, and restricted cash Related party liabilities us-gaap_IncreaseDecreaseInDueToRelatedParties New Accounting Pronouncements, Policy [Policy Text Block] us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations Cash, cash equivalents, and restricted cash at beginning of period Cash, cash equivalents, and restricted cash at end of period Antidilutive Securities, Name [Domain] Statement [Table] Reclassification, Comparability Adjustment [Policy Text Block] Credit Facility [Axis] Cash paid for amounts included in the measurement of lease liabilities - Operating leases Credit Facility [Domain] Revolving Credit Facility [Member] Other direct operating costs, related party Other costs from related parties incurred during the reporting period related to other revenue generating activities. us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 Debt Instrument, Basis Spread on Variable Rate Asset retirement obligations, related party (includes $250,000 and $250,000 non-related party at March 31, 2026 and December 31, 2025, respectively) Current portion of the carrying amount of a liability for related party portion of an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity Capital contributions from non-controlling interests Line of Credit Facility, Lender [Domain] us-gaap_EquityMethodInvestmentOwnershipPercentage Equity Method Investment, Ownership Percentage Lender Name [Axis] Product and Service [Domain] Product and Service [Axis] Ownership [Axis] Ownership [Domain] Consolidated Entities [Axis] us-gaap_PropertyPlantAndEquipmentUsefulLife Property, Plant, and Equipment, Useful Life (Year) Consolidated Entities [Domain] us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear 2026 (excluding the three-months ended March 31, 2026) us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue Total lease payments Weighted-average discount rate - Operating leases 2027 Schedule of Maturities of Long-Term Debt [Table Text Block] 2026 (excluding the three-months ended March 31, 2026) Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] 2029 Commitments and Contingencies Disclosure [Text Block] 2028 Statement [Line Items] 2030 Common stock, shares issued (in shares) Common stock, shares outstanding (in shares) Balances (in shares) Balances (in shares) Award Type [Domain] Common stock, shares authorized (in shares) Property, Plant and Equipment, Depreciation [Table Text Block] Tabular disclosure of depreciation for physical assets used in the normal conduct of business and not intended for resale. Common stock, no par value (10,000,000 authorized shares; Issued and outstanding shares - 6,600,000 at March 31, 2026 and 6,575,000 at December 31, 2025) Accounts payable us-gaap_PolicyTextBlockAbstract Accounting Policies Capital contribution non-controlling interests us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_TableTextBlock Notes Tables Advances on line of credit us-gaap_AccruedProfessionalFeesCurrent Professional services Related party liabilities Interest and other income, net The amount of interest income (loss) and other income (loss) recognized during the period. Related Party [Member] Employee compensation and benefits Significant Accounting Policies [Text Block] us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount Less imputed interest Long-term lease liabilities, less current portion Total us-gaap_OperatingLeaseLiability Operating Lease, Liability Schedule of Related Party Transactions [Table Text Block] Other accrued liabilities Total other accrued liabilities Current portion of lease liabilities Current portion of long-term debt, net us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo 2028 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour 2030 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree 2029 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths 2027 us-gaap_LongTermDebt Long-Term Debt Statement of Stockholders' Equity [Abstract] Statement of Cash Flows [Abstract] Equity Components [Axis] Lease liabilities Equity Component [Domain] Additional Paid-in Capital [Member] Retained Earnings [Member] Maintenance and supplies ams_PolicyTable Equipment included in accounts payable and accrued liabilities Other direct operating costs Costs of revenue: us-gaap_CostOfRevenue Cost of Revenue Deferred income taxes MEXICO Share-Based Payment Arrangement, Option [Member] Supplemental cash flow disclosure us-gaap_AccountsReceivableNet Accounts Receivable, after Allowance for Credit Loss Current liabilities: us-gaap_LiabilitiesCurrent Total current liabilities us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] Rental Income from Medical Services [Member] Represents rental income from medical services. GKCE [Member] Represents Gamma Knife Center Ecuador. Secured Overnight Financing Rate (SOFR) [Member] Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue [Table Text Block] Accounts receivable, net of allowance for credit losses of $980,000 and $980,000 at March 31, 2026 and December 31, 2025, respectively Patient Income [Member] Represents patient income. Lease, Cost [Table Text Block] Geographic Distribution, Domestic [Member] Geographic Distribution, Foreign [Member] Geographic Distribution [Axis] Geographic Distribution [Domain] Other Commitments [Table] Long-Term Debt [Text Block] us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment Accumulated depreciation Common stock, no par value (in dollars per share) us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest Loss before income taxes Additional paid-in capital Segment Reporting, Policy [Policy Text Block] Non-controlling interests in subsidiaries Prepaid expenses and other current assets us-gaap_PaymentsToAcquireRealEstate Payments to Acquire Real Estate us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Payment for purchases of property and equipment Lessee, Operating Leases [Text Block] us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation Stock-based compensation expense us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders Cash distributions to non-controlling interests us-gaap_DebtInstrumentCarryingAmount Long-Term Debt, Gross Long-Term Debt, Gross us-gaap_MinorityInterestOwnershipPercentageByParent Noncontrolling Interest, Ownership Percentage by Parent Non-US [Member] us-gaap_DebtInstrumentFaceAmount Debt Instrument, Face Amount Current assets: ams_DebtInstrumentNumberOfInstallments Debt Instrument, Number of Installments The number of installments under the debt instrument. us-gaap_AssetsCurrent Total current assets Vested restricted stock awards us-gaap_GrossProfit Gross margin Interest income us-gaap_InterestIncomeInterestEarningAsset Debt Instrument, Name [Domain] us-gaap_DebtInstrumentInterestRateStatedPercentage Debt Instrument, Interest Rate, Stated Percentage Vested restricted stock awards (in shares) us-gaap_DebtInstrumentInterestRateEffectivePercentage Debt Instrument, Interest Rate, Effective Percentage Related and Nonrelated Parties [Axis] Schedule of Long-Term Debt Instruments [Table] ams_PercentageOfSiteModifications Percentage of Site Modifications Percentage of site modifications. Debt Instrument [Axis] Operating activities: ams_OperatingLeaseMonthlyExpense Operating Lease, Monthly Expense Amount of operating lease expense per month. Excludes sublease income. Investing activities: ams_DebtInstrumentCovenantMinimumUnrestrictedCash Debt Instrument, Covenant, Minimum Unrestricted Cash Minimum amount of unrestricted cash maintain under covenant of debt instrument. us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities Bristol [Member] Represents Bristol. Financing activities: us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash (used in) provided by financing activities GKCE Loan Two [Member] Represents GKCE Loan Two. GKCE Loans [Member] Represents GKCE Loans. ams_DebtInstrumentNumberOfMonthlyInstallment Debt Instrument, Number of Monthly Installment Represents number of monthly installment under debt instrument. GKCE Loan One [Member] Represents GKCE Loan One. Accounting Policies [Abstract] Segments [Domain] us-gaap_DeferredFinanceCostsGross Debt Issuance Costs, Gross RI Companies [Member] Related to RI companies acquisition. Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue and Long-Lived Asset [Table] Allowance for doubtful accounts Other Liabilities Disclosure [Text Block] ams_BusinessCombinationNetPaymentTerms Business Combination, Net Payment Terms (Year) Represents the net payment terms under a business combination. Single-Unit Radiation Therapy Facilities [Member] Represent single-unit radiation therapy facilities. Segments [Axis] Radiation Therapy Facility in Puebla, Mexico [Member] Represents Radiation Therapy Facility in Puebla, Mexico. Income Statement [Abstract] Small Office Sublease in Downers Grove [Member] Represents small office sublease in Downers Grove. Small Office Sublease in San Francisco [Member] Represents small office sublease in San Francisco. Liquidity [Policy Text Block] Disclosure of accounting policy for liquidity. us-gaap_NumberOfReportableSegments Number of Reportable Segments Clinic Space in Woonsocket, RI [Member] Represents Clinic Space in Woonsocket, RI. Facility in Warwick, RI [Member] Represents facility in Warwick, RI. us-gaap_PurchaseObligation Purchase Obligation Net loss attributable to American Shared Hospital Services Net loss attributable to American Shared Hospital Services Net income (loss) Accretion of debt issuance costs Amortization of Debt Issuance Costs us-gaap_AreaOfRealEstateProperty Area of Real Estate Property (Square Foot) DFC Loan [Member] Represents the DFC loan. Income Tax Disclosure [Text Block] Restricted Stock [Member] Stand-alone Facility in Lima, Peru [Member] Represents the stand-alone office in Lima, Peru. Thereafter Represents the Lessee operating lease liability payments that are due after year 4. Accounting Standards Update and Change in Accounting Principle [Table] Schedule of non-cash investing and financing activities Costs incurred to maintain equipment Asser retirement obligations, non-related party ams_AccruedLiabilitesOtherCurrent Other The amount of accrued liabilities classified as current not specifically disclosed. us-gaap_RelatedPartyTransactionAmountsOfTransaction Total related party transactions Related and Nonrelated Parties [Domain] us-gaap_DeferredFinanceCostsNet Debt Issuance Costs, Net ams_AccruedOperatingCostsCurrent Operating costs The amount of accrued operating costs classified as current. Related Party Transaction [Table] Related Party Transactions Disclosure [Text Block] Other receivables ams_LongtermServiceCommitmentAmount Long-Term Service Commitment, Amount The amount of long-term service commitment. us-gaap_RepaymentsOfLongTermDebt Principal payments on long-term debt Statement of Financial Position [Abstract] ams_LongtermServiceCommitmentPeriod Long-Term Service Commitment, Period (Year) The period of the long-term service commitment. LINAC System [Member] Represents the LINAC system. Income tax (refunds) GKF Subsidiary [Member] Represents the GKF subsidiary. Tax receivables DFC Loan, Tranche Two [Member] Represents tranche two of the DFC loan. US Subsidiary Of Elekta Member Represents the US subsidiary Of Elekta. DFC Loan, Tranche One [Member] Represents tranche one of the DFC loan. us-gaap_PaymentsToMinorityShareholders Distributions to non-controlling interests Other assets Document Type HSJ [Member] Represents Hospital San Javier, S.A. de C.V. ("HSJ"). The Credit Agreement, 2024 Supplemental Term Loan [Member] Represents the 2024 supplemental term loan part of the credit agreement. Newco Guadalajara [Member] Represents Newco in Guadalajara. Document Information [Line Items] Document Quarterly Report us-gaap_LesseeOperatingLeaseTermOfContract Lessee, Operating Lease, Term of Contract (Year) Weighted-average remaining lease term - Operating leases in years (Year) Document Information [Table] ams_DebtInstrumentVariableRateFloor Debt Instrument, Variable Rate, Floor Represents the variable rate floor for a debt instrument. us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) Antidilutive Securities [Axis] Entity Interactive Data Current Document Transition Report Weighted average common shares for diluted loss per share (in shares) Net loss per share: us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements (in shares) Weighted average common shares for basic loss per share (in shares) us-gaap_DebtInstrumentTerm Debt Instrument, Term (Year) Antidilutive Security, Excluded EPS Calculation [Table] Basic loss per share (in dollars per share) Direct Patient Services [Member] Represents direct patient services. Effective Income Tax Rate Reconciliation [Table] Medical Equipment Leasing [Member] Represents medical equipment leasing. Office Equipment [Member] Intangible asset Document Fiscal Period Focus Document Fiscal Year Focus Investment, Name [Domain] Depreciation and amortization Depreciation, amortization, and other Restricted cash Amendment Flag us-gaap_SubleaseIncome Sublease Income Sublease income Common Stock [Member] Goodwill Document Period End Date Property, Plant, and Equipment [Text Block] Long-Lived Asset, Class [Domain] Legal Entity [Axis] Operating lease cost Construction in Progress [Member] us-gaap_LeaseCost Total lease cost Business Combination [Domain] Entity File Number Entity Tax Identification Number Business Combination [Axis] Entity [Domain] Entity Central Index Key us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired Business Combination, Voting Equity Interest Acquired, Percentage Entity Registrant Name Entity Current Reporting Status Entity Incorporation, State or Country Code Current Fiscal Year End Date Entity Filer Category Entity Shell Company Entity Emerging Growth Company Entity Small Business us-gaap_OperatingIncomeLoss Operating loss Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Interest expense Interest expense Revenues: us-gaap_BusinessCombinationConsiderationTransferred1 Business Combination, Consideration Transferred Entity Address, State or Province Entity Address, City or Town Retained earnings Entity Address, Address Line One City Area Code Local Phone Number Entity Address, Postal Zip Code us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNumberOfUnits Property Subject to or Available for Operating Lease, Number of Units Title of 12(b) Security Security Exchange Name Trading Symbol Class of Stock [Axis] Variable Rate [Domain] Revenue [Policy Text Block] Related Party Transaction [Domain] Entity Common Stock, Shares Outstanding Related Party Transaction [Axis] Earnings Per Share [Text Block] us-gaap_NetIncomeLossAttributableToNoncontrollingInterest Less: net loss attributable to non-controlling interests Net loss Net loss Property, Plant, and Equipment [Table] Investment, Name [Axis] Accounts payable, asset retirement obligation and other accrued liabilities Amount of accounts payable, asset retirement obligations and other accrued liabilities as of balance sheet date. Long-Lived Asset, Class [Axis] us-gaap_Assets Total assets TOTAL ASSETS Cash and cash equivalents Cash and cash equivalents Geographical [Domain] Geographical [Axis] Equipment purchases and de-install costs ams_PropertyPlantAndEquipmentGrossExcludingLand Property and equipment, gross Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale, excluding land. Diluted loss per share (in dollars per share) Property and equipment, net Net property and equipment Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale, excluding land. Non cash lease expense ams_NoncashLeaseExpense The amount of noncash lease expense. ams_NumberOfMedicalCenters Number of Medical Centers The number of medical centers. Other Liabilities [Table Text Block] Interest Gamma Knife and PBRT Equipment [Member] Represents Gamma Knife and PBRT equipment. us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest Total shareholders' equity Balances Balances ams_NumberOfSingleunitFacilities Number of Single-unit Facilities The number of single-unit facilities. Lima, Peru and Guayaquil, Ecuador [Member] Represents Lima, Peru and Guayaquil, Ecuador. Shareholders' equity: PBRT Equipment [Member] Represents PBRT equipment. Medical Equipment and Facilities [Member] Represents medical equipment and facilities. Parent [Member] Medical and Office Equipment [Member] Represents medical and office equipment. Noncontrolling Interest [Member] Fifth Third Bank, N.A. [Member] Represents Fifth Third Bank, N.A. The Credit Agreement [Member] Represents the Credit Agreement. us-gaap_StockholdersEquity Total equity-American Shared Hospital Services The Credit Agreement, Second Loan Facility [Member] The second loan facility of the credit agreement. ams_NumberOfDebtInstruments Number of Debt Instruments The number of debt instruments. VAT credits The Credit Agreement, Third Loan Facility [Member] Represents the third loan facility of the credit agreement. ams_DebtInstrumentCovenantMaximumFundedDebtToEditdaRatio Debt Instrument, Covenant, Maximum Funded Debt to EDITDA Ratio The maximum funded debt to EBITDA ratio allowed under the covenant of the debt instrument. ams_DebtInstrumentCovenantMinimumFixedChargeCoverageRatio Debt Instrument, Covenant, Minimum Fixed Charge Coverage Ratio Requirement for fixed charge coverage ratio under the debt agreement. Right of use assets, net Operating Lease, Right-of-Use Asset ecd_Rule10b51ArrTrmntdFlag Rule 10b5-1 Arrangement Terminated [Flag] Property, Plant, and Equipment [Table Text Block] Revenues Leasing Revenue us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax Revenue from Contract with Customer, Including Assessed Tax ecd_Rule10b51ArrAdoptedFlag Rule 10b5-1 Arrangement Adopted [Flag] Commitments (see Note 8)