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Warrants and Derivative Liabilities - Schedule of Assumptions Used to Calculate the Fair Value of Warrants (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended							0 Months Ended	3 Months Ended					0 Months Ended
	Apr. 04, 2012	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 20, 2012	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Oct. 09, 2013	Dec. 19, 2014	Jun. 05, 2012	Nov. 15, 2013	Nov. 13, 2014
Derivative [Line Items]
Risk-free interest rate	0.44%us-gaap_FairValueAssumptionsRiskFreeInterestRate	0.12%us-gaap_FairValueAssumptionsRiskFreeInterestRate	0.10%us-gaap_FairValueAssumptionsRiskFreeInterestRate	0.21%us-gaap_FairValueAssumptionsRiskFreeInterestRate	0.20%us-gaap_FairValueAssumptionsRiskFreeInterestRate	0.23%us-gaap_FairValueAssumptionsRiskFreeInterestRate	0.23%us-gaap_FairValueAssumptionsRiskFreeInterestRate	0.33%us-gaap_FairValueAssumptionsRiskFreeInterestRate
Expected annual dividend yield	15.00%us-gaap_FairValueAssumptionsExpectedDividendRate	16.50%us-gaap_FairValueAssumptionsExpectedDividendRate	15.50%us-gaap_FairValueAssumptionsExpectedDividendRate	16.70%us-gaap_FairValueAssumptionsExpectedDividendRate	16.50%us-gaap_FairValueAssumptionsExpectedDividendRate	16.50%us-gaap_FairValueAssumptionsExpectedDividendRate	15.00%us-gaap_FairValueAssumptionsExpectedDividendRate	16.00%us-gaap_FairValueAssumptionsExpectedDividendRate
Expected volatility	75.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate	68.63%us-gaap_FairValueAssumptionsExpectedVolatilityRate	66.26%us-gaap_FairValueAssumptionsExpectedVolatilityRate	65.80%us-gaap_FairValueAssumptionsExpectedVolatilityRate	66.91%us-gaap_FairValueAssumptionsExpectedVolatilityRate	73.50%us-gaap_FairValueAssumptionsExpectedVolatilityRate	70.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate	71.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate
Term (years)	2 years 6 months	9 months	1 year	1 year 3 months 4 days	1 year 6 months 4 days	1 year 9 months 4 days	2 years 4 days	2 years 3 months 11 days
Post Modification
Derivative [Line Items]
Risk-free interest rate									0.25%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_RangeAxis = amsc_PostModificationMember
Expected annual dividend yield									16.50%us-gaap_FairValueAssumptionsExpectedDividendRate / us-gaap_RangeAxis = amsc_PostModificationMember
Expected volatility									72.50%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_RangeAxis = amsc_PostModificationMember
Term (years)									1 year 9 months 15 days
Pre Modification
Derivative [Line Items]
Risk-free interest rate									0.25%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_RangeAxis = amsc_PreModificationMember
Expected annual dividend yield									16.50%us-gaap_FairValueAssumptionsExpectedDividendRate / us-gaap_RangeAxis = amsc_PreModificationMember
Expected volatility									72.50%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_RangeAxis = amsc_PreModificationMember
Term (years)									1 year 9 months 15 days
Senior Convertible Note Warrant
Derivative [Line Items]
Risk-free interest rate	1.19%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	1.17%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	1.02%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	1.13%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	0.67%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	0.75%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	0.63%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	0.77%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember		0.73%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	1.00%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	1.07%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	0.98%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	1.11%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember
Expected volatility	80.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	75.60%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	71.98%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	71.90%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	71.74%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	80.60%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	80.90%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	80.80%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember		70.42%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	72.38%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	76.20%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	83.50%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	80.99%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember
Term (years)	5 years 6 months	3 years 9 months 4 days	4 years 4 days	4 years 3 months 7 days	4 years 6 months 4 days	4 years 9 months 4 days	5 years 4 days	5 years 3 months 11 days		2 years 6 months 4 days	2 years 9 months 4 days	3 years 4 days	3 years 3 months 4 days	3 years 6 months 4 days
Fair value	7.0amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	2.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	2.5amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	3.0amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	3.4amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	4.4amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	7.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	8.6amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember		$ 0.3amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	$ 0.5amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	$ 1.5amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	$ 2.3amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember	$ 2.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember
Senior Convertible Note Warrant | Post Modification
Derivative [Line Items]
Risk-free interest rate															1.05%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember / us-gaap_RangeAxis = amsc_PostModificationMember
Expected volatility															71.45%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember / us-gaap_RangeAxis = amsc_PostModificationMember
Term (years)															3 years 11 months 27 days
Fair value															3.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember / us-gaap_RangeAxis = amsc_PostModificationMember
Senior Convertible Note Warrant | Pre Modification
Derivative [Line Items]
Risk-free interest rate															1.05%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember / us-gaap_RangeAxis = amsc_PreModificationMember
Expected volatility															71.45%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember / us-gaap_RangeAxis = amsc_PreModificationMember
Term (years)															3 years 11 months 27 days
Fair value															2.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorConvertibleNoteWarrantMember / us-gaap_RangeAxis = amsc_PreModificationMember
Senior Secured Term Loan First Warrant
Derivative [Line Items]
Risk-free interest rate		1.24%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	1.09%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	1.20%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.70%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.75%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.64%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.80%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember				1.13%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	1.04%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	1.18%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember		1.10%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.77%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember
Expected volatility		74.79%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	72.10%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	72.30%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	72.01%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	80.14%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	81.18%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	80.32%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember				78.30%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	82.75%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	80.73%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember		67.01%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	79.99%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember
Term (years)		3 years 11 months 5 days	4 years 2 months 5 days	4 years 5 months 5 days	4 years 8 months 5 days	4 years 11 months 5 days	5 years 2 months 5 days	5 years 5 months 9 days			0 years	3 years 2 months 5 days	3 years 5 months 5 days	3 years 8 months 5 days		2 years 11 months 16 days	5 years 6 months
Fair value		0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.4amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.5amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember			0amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember		0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember	0.4amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember
Senior Secured Term Loan First Warrant | Post Modification
Derivative [Line Items]
Risk-free interest rate																		1.00%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember / us-gaap_RangeAxis = amsc_PostModificationMember
Expected volatility																		72.64%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember / us-gaap_RangeAxis = amsc_PostModificationMember
Term (years)																		4 years 18 days
Fair value																		0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember / us-gaap_RangeAxis = amsc_PostModificationMember
Senior Secured Term Loan First Warrant | Pre Modification
Derivative [Line Items]
Risk-free interest rate																		1.00%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember / us-gaap_RangeAxis = amsc_PreModificationMember
Expected volatility																		72.64%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember / us-gaap_RangeAxis = amsc_PreModificationMember
Term (years)																		4 years 18 days
Fair value																		0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanFirstWarrantMember / us-gaap_RangeAxis = amsc_PreModificationMember
Senior Secured Term Loan Second Warrant
Derivative [Line Items]
Risk-free interest rate		1.89%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember										1.65%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember	1.57%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember	1.76%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember		1.65%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember		1.55%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember
Expected volatility		80.37%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember										78.10%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember	80.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember	79.73%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember		71.82%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember		76.97%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember
Term (years)		5 years 4 months 13 days									0 years	4 years 7 months 13 days	4 years 10 months 13 days	5 years 1 month 13 days		4 years 4 months 28 days		5 years 5 months 27 days
Fair value		0.3amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember									0amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember	0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember	0.3amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember	0.3amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember		0.1amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember		0.3amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanSecondWarrantMember
Senior Secured Term Loan New Warrant
Derivative [Line Items]
Risk-free interest rate										1.41%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember	1.73%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember					1.74%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember
Expected volatility										74.60%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember	77.43%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember					70.26%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember
Term (years)										5 years 3 months	5 years 6 months					5 years 6 months 11 days
Fair value										0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember	0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember					0.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_SeniorSecuredTermLoanNewWarrantMember
November 2014 Warrant
Derivative [Line Items]
Risk-free interest rate										1.28%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember	1.61%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember								1.64%us-gaap_FairValueAssumptionsRiskFreeInterestRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember
Expected volatility										75.96%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember	78.00%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember								72.86%us-gaap_FairValueAssumptionsExpectedVolatilityRate / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember
Term (years)										4 years 7 months 13 days	4 years 10 months 13 days								5 years
Fair value										$ 2.5amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember	$ 3.2amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember								$ 4.3amsc_WarrantInstrumentsFairValueDisclosure / us-gaap_ClassOfWarrantOrRightAxis = amsc_NovemberTwoThousandFourteenWarrantMember

X

- Definition

Warrant instruments, fair value disclosure.

+ References

No definition available.

+ Details

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X

- Definition

Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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X

- Definition

Period the instrument, asset or liability is expected to be outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price.

+ References

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Risk-free interest rate assumption used in valuing an instrument.

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