XML 42 R53.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Debt - Additional Information (Detail) (USD $) | 0 Months Ended | 3 Months Ended | 9 Months Ended | 0 Months Ended | 3 Months Ended | 0 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 13, 2014 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2014 | Dec. 31, 2013 | Mar. 02, 2014 | Mar. 31, 2014 | Oct. 09, 2013 | Apr. 04, 2012 | Nov. 15, 2013 | Dec. 19, 2014 | Jun. 05, 2012 | Mar. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Dec. 31, 2012
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants |  | $ 3,914,000 us-gaap_DerivativeLiabilitiesCurrent |  | $ 3,914,000 us-gaap_DerivativeLiabilitiesCurrent |  |  | $ 2,601,000 us-gaap_DerivativeLiabilitiesCurrent |  |  |  |  |  |  |  |  |
Non-cash interest expense amortization of debt discount |  | 100,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount | 1,100,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount | 500,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount | 5,900,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount |  |  |  |  |  |  |  |  |  |  |
Percentage of stock discount |  |  |  | 85.00%amsc_PercentageOfStockDiscount |  |  |  |  |  |  |  |  |  |  |  |
Number of trading days for valuation of shares |  |  |  | 10 days |  |  |  |  |  |  |  |  |  |  |  |
Non-cash interest expense issuing stock at discount |  |  | 1,800,000 amsc_NonCashInterestExpenseIssuingStockAtDiscount |  | 1,800,000 amsc_NonCashInterestExpenseIssuingStockAtDiscount |  |  |  |  |  |  |  |  |  |  |
Legal and origination costs |  |  |  | 10,188,000 us-gaap_LegalFees |  |  |  |  |  |  |  |  |  |  |  |
Interest expense |  | 400,000 us-gaap_InterestExpense | 1,600,000 us-gaap_InterestExpense | 1,400,000 us-gaap_InterestExpense | 7,200,000 us-gaap_InterestExpense |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Maturity Date, Description |  |  |  | As part of the Hercules Second Amendment, this Minimum Threshold was amended to be the lower of $5.0 million or the aggregate outstanding principal balance of the Term Loans. As of December 31, 2014, the Minimum Threshold was $5.0 million. If the Company raises $10.0 million in new capital by June 30, 2015, the Minimum Threshold will be reduced to the lesser of $2.0 million or the aggregate outstanding principal balance of the Term Loans. |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from sale of common stock | 9,100,000 us-gaap_ProceedsFromIssuanceOfCommonStock | 9,100,000 us-gaap_ProceedsFromIssuanceOfCommonStock |  | 9,114,000 us-gaap_ProceedsFromIssuanceOfCommonStock |  |  |  |  |  |  |  |  |  |  |  |
Combined principal balances of the term loans |  |  | 10,411,000 us-gaap_DebtInstrumentCarryingAmount |  | 10,411,000 us-gaap_DebtInstrumentCarryingAmount |  |  |  |  |  |  |  | 15,380,000 us-gaap_DebtInstrumentCarryingAmount | 10,411,000 us-gaap_DebtInstrumentCarryingAmount | 14,389,000 us-gaap_DebtInstrumentCarryingAmount |
Capital Ventures International |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt conversion, shares issued |  |  |  |  |  | 6,600,000 us-gaap_DebtConversionConvertedInstrumentSharesIssued1 / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember |  |  |  |  |  |  |  |  |  |
Loss on extinguishment of debt |  |  |  |  |  |  | (5,200,000)us-gaap_GainsLossesOnExtinguishmentOfDebt / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember |  |  |  |  |  |  |  |  |
Convertible Notes |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-cash interest expense amortization of debt discount |  |  | 900,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  | 3,600,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |  |  |  |  |
Convertible Notes | Capital Ventures International |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds after fees and expenses of purchase agreement |  |  |  |  |  |  |  |  | 23,200,000 us-gaap_ProceedsFromConvertibleDebt / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
Conversion price |  |  |  |  |  |  |  |  | $ 4.85 us-gaap_DebtInstrumentConvertibleConversionPrice1 / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
Premium over closing price, percentage |  |  |  |  |  |  |  |  | 20.00%amsc_PurchaseCommitmentPremiumOfClosingPricePercent / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
Period before first installment payment |  |  |  |  |  |  |  |  | 4 months |  |  |  |  |  |  |
Shares registered for resale |  |  |  |  |  |  |  |  | 10,262,311 amsc_CommonStockResaleShares / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
Debt, face amount |  |  |  |  |  |  |  |  | 3,800,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
Number of shares received from warrants received to purchase common stock |  |  |  |  |  |  |  |  | 3,094,060 amsc_PurchaseCommitmentIssuanceOfWarrantsSharesOfCommonStock / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
Strike price per share |  |  |  |  |  |  |  | $ 2.61 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember | $ 5.45 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
Fair value of warrants at issuance |  |  |  |  |  |  |  |  | 7,000,000 amsc_PurchaseCommitmentIssuanceOfWarrantsFairValueOfSharesOfCommonStock / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleNotesPayableMember |  |  |  |  |  |  |
New Unsecured Senior Convertible Note |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion price |  |  |  |  |  |  |  |  | $ 4.85 us-gaap_DebtInstrumentConvertibleConversionPrice1 / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember |  |  |  |  |  |  | $ 3.19 us-gaap_DebtInstrumentConvertibleConversionPrice1 / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember
Debt conversion, shares issued |  |  |  |  |  | 6,600,000 us-gaap_DebtConversionConvertedInstrumentSharesIssued1 / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember |  |  |  |  |  |  |  |  |  |
New Unsecured Senior Convertible Note | Capital Ventures International |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrants |  | 500,000 us-gaap_DerivativeLiabilitiesCurrent / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember |  | 500,000 us-gaap_DerivativeLiabilitiesCurrent / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember |  |  |  |  |  |  |  |  |  |  |  |
Increase in derivative liability |  |  |  | 1,500,000 us-gaap_DerivativeLossOnDerivative / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember |  |  |  |  |  |  |  |  |  |  |  |
Total debt discount being amortized into interest expense |  | 13,100,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember |  | 13,100,000 us-gaap_DebtInstrumentUnamortizedDiscount / us-gaap_DebtInstrumentAxis = amsc_CapitalVenturesInternationalMember / us-gaap_LongtermDebtTypeAxis = amsc_NewUnsecuredSeniorConvertibleNoteMember |  |  |  |  |  |  |  |  |  |  |  |
Senior Secured Loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares received from warrants received to purchase common stock |  |  |  |  |  |  |  |  |  | 256,410 amsc_PurchaseCommitmentIssuanceOfWarrantsSharesOfCommonStock / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |
Strike price per share |  |  |  | $ 1.70 invest_InvestmentWarrantsExercisePrice / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  | $ 1.95 invest_InvestmentWarrantsExercisePrice / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |
Senior Secured Loan | Hercules Technology Growth Capital |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, face amount |  |  |  |  |  |  |  |  |  | 10,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  | 10,000,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |
Number of shares received from warrants received to purchase common stock |  |  |  |  |  |  |  |  |  | 256,410 amsc_PurchaseCommitmentIssuanceOfWarrantsSharesOfCommonStock / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | 588,235 amsc_PurchaseCommitmentIssuanceOfWarrantsSharesOfCommonStock / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | 139,276 amsc_PurchaseCommitmentIssuanceOfWarrantsSharesOfCommonStock / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |
Strike price per share |  |  | $ 1.95 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | $ 1.70 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  | $ 1.95 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | $ 1.10 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | $ 3.59 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |
Fair value of warrants at issuance |  |  |  |  |  |  |  |  |  |  |  | 400,000 amsc_PurchaseCommitmentIssuanceOfWarrantsFairValueOfSharesOfCommonStock / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |
Non-cash interest expense amortization of debt discount |  |  | 100,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | 100,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | 400,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |
Legal and origination costs |  |  | 200,000 us-gaap_LegalFees / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  | 300,000 us-gaap_LegalFees / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |
Net proceeds from debt |  |  |  |  |  |  |  |  |  | 9,800,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  | 9,700,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |
Interest rate on loan |  |  |  |  |  |  |  |  |  |  |  | 11.00%us-gaap_DebtInstrumentInterestRateStatedPercentage / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |
End of term fee |  |  |  | 500,000 amsc_DebtInstrumentEndOfTermFee / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  | 500,000 amsc_DebtInstrumentEndOfTermFee / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |
Interest expense |  |  |  | 1,000,000 us-gaap_InterestExpense / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  | 1,200,000 us-gaap_InterestExpense / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |
Total debt discount being amortized into interest expense |  | 100,000 us-gaap_AmortizationOfDebtDiscountPremium / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | 100,000 us-gaap_AmortizationOfDebtDiscountPremium / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | 400,000 us-gaap_AmortizationOfDebtDiscountPremium / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember | 100,000 us-gaap_AmortizationOfDebtDiscountPremium / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |
Minimum amount of proceeds from specified asset dispositions for mandatory prepayment feature |  | 1,000,000 amsc_MinimumAmountOfProceedsFromSpecifiedAssetDispositionsForMandatoryPrepaymentFeature / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  | 1,000,000 amsc_MinimumAmountOfProceedsFromSpecifiedAssetDispositionsForMandatoryPrepaymentFeature / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |
Outstanding principal balance |  | 7,700,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  | 7,700,000 us-gaap_LongTermDebt / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |
Covenant, unrestricted cash balance requirement |  | 5,000,000 amsc_DebtInstrumentCovenantUnrestrictedCashBalanceRequirement / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  | 5,000,000 amsc_DebtInstrumentCovenantUnrestrictedCashBalanceRequirement / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |
Repayments of term loan |  |  |  | 2,000,000 us-gaap_RepaymentsOfDebt / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |
Senior Secured Loan | Hercules Technology Growth Capital | Second Amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt, face amount |  |  |  |  |  |  |  |  |  |  | 1,500,000 us-gaap_DebtInstrumentFaceAmount / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |
Number of shares received from warrants received to purchase common stock |  |  |  |  |  |  |  |  |  |  | 588,235 amsc_PurchaseCommitmentIssuanceOfWarrantsSharesOfCommonStock / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |
Strike price per share |  |  |  |  |  |  |  |  |  |  | $ 1.10 invest_InvestmentWarrantsExercisePrice / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |
Legal and origination costs |  | 100,000 us-gaap_LegalFees / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from debt |  |  |  |  |  |  |  |  |  |  | 1,400,000 us-gaap_ProceedsFromIssuanceOfDebt / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |
End of term fee |  |  |  | 100,000 amsc_DebtInstrumentEndOfTermFee / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |
Interest expense |  |  |  | 200,000 us-gaap_InterestExpense / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |
Future raise in capital |  | 10,000,000 amsc_AdditionalCapital / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  | 10,000,000 amsc_AdditionalCapital / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LineOfCreditFacilityAxis = amsc_SecondAmendmentMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Maturity Date |  |  |  | Jun. 01, 2017 |  |  |  |  |  |  |  |  |  |  |  |
Senior Secured Loan | Hercules Technology Growth Capital | Minimum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Prime rate |  |  |  |  |  |  |  |  |  |  |  | 3.75%amsc_PrimeRate / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember / us-gaap_RangeAxis = us-gaap_MinimumMember |  |  |  |
Senior Secured Loan | Hercules Technology Growth Capital | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-cash interest expense amortization of debt discount |  | $ 100,000 amsc_NonCashInterestExpenseAmortizationOfDebtDiscount / us-gaap_DebtInstrumentAxis = amsc_HerculesTechnologyGrowthCapitalMember / us-gaap_LongtermDebtTypeAxis = amsc_SeniorSecuredLoanMember / us-gaap_RangeAxis = us-gaap_MaximumMember |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Additional Capital + References No definition available. + Details
Name: | amsc_AdditionalCapital
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Common stock available for use as payment for principal registered for resale under the Securities Act. + References No definition available. + Details
Name: | amsc_CommonStockResaleShares
Namespace Prefix: | amsc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt instrument covenant unrestricted cash balance requirement. + References No definition available. + Details
Name: | amsc_DebtInstrumentCovenantUnrestrictedCashBalanceRequirement
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Debt instrument, end of term fee. + References No definition available. + Details
Name: | amsc_DebtInstrumentEndOfTermFee
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Minimum amount of proceeds from specified asset dispositions for mandatory prepayment feature. + References No definition available. + Details
Name: | amsc_MinimumAmountOfProceedsFromSpecifiedAssetDispositionsForMandatoryPrepaymentFeature
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Non-cash interest expense amortization of debt discount. + References No definition available. + Details
Name: | amsc_NonCashInterestExpenseAmortizationOfDebtDiscount
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Non-cash interest expense issuing stock at discount. + References No definition available. + Details
Name: | amsc_NonCashInterestExpenseIssuingStockAtDiscount
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of trading period for valuation of Shares. + References No definition available. + Details
Name: | amsc_NumberOfTradingPeriodForValuationOfShares
Namespace Prefix: | amsc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of stock discount. + References No definition available. + Details
Name: | amsc_PercentageOfStockDiscount
Namespace Prefix: | amsc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period before first installment payment. + References No definition available. + Details
Name: | amsc_PeriodBeforeFirstInstallmentPayment
Namespace Prefix: | amsc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Prime rate. + References No definition available. + Details
Name: | amsc_PrimeRate
Namespace Prefix: | amsc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Purchase commitment, issuance of warrants, fair value of shares of common stock. + References No definition available. + Details
Name: | amsc_PurchaseCommitmentIssuanceOfWarrantsFairValueOfSharesOfCommonStock
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Purchase commitment issuance of warrants shares of common stock. + References No definition available. + Details
Name: | amsc_PurchaseCommitmentIssuanceOfWarrantsSharesOfCommonStock
Namespace Prefix: | amsc_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Purchase commitment, premium of closing price, percent. + References No definition available. + Details
Name: | amsc_PurchaseCommitmentPremiumOfClosingPricePercent
Namespace Prefix: | amsc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Exercise price of the warrants. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column A + Details
Name: | invest_InvestmentWarrantsExercisePrice
Namespace Prefix: | invest_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.8) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 5 + Details
Name: | us-gaap_AmortizationOfDebtDiscountPremium
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586 + Details
Name: | us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 + Details
Name: | us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The price per share of the conversion feature embedded in the debt instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870 + Details
Name: | us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDateDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
Name: | us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Current Liabilities -URI http://asc.fasb.org/extlink&oid=6509677 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13495-108611 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=34720828&loc=SL20225862-175312 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 + Details
Name: | us-gaap_DerivativeLiabilitiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of decrease in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeLossOnDerivative
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12317-112629 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12355-112629 + Details
Name: | us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of the cost of borrowed funds accounted for as interest expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.9) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 9 -Article 9 + Details
Name: | us-gaap_InterestExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.3) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_LegalFees
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Article 9 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20, 22 -Article 5 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash inflow from the issuance of a long-term debt instrument which can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromConvertibleDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt. + References No definition available. + Details
Name: | us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations. + References No definition available. + Details
Name: | us-gaap_RepaymentsOfDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=amsc_CapitalVenturesInternationalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=amsc_NewUnsecuredSeniorConvertibleNoteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=amsc_SeniorSecuredLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_ConvertibleNotesPayableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |