Commission as percentage of gross proceeds from sale of common Stock.

No definition available.

Name:	amsc_CommissionAsPercentageOfGrossProceedsFromSaleOfCommonStock
Namespace Prefix:	amsc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of warrants issued to purchase common stock.

+ References

No definition available.

+ Details

Name:	amsc_NumberOfWarrantsIssuedToPurchaseCommonStock
Namespace Prefix:	amsc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Warrants to purchase one share of common stock.

+ References

No definition available.

+ Details

Name:	amsc_WarrantsToPurchaseOneShareOfCommonStock
Namespace Prefix:	amsc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

+ References

+ Details

Name:	us-gaap_CommonStockValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of common units issued of limited liability company (LLC).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

+ Details

Name:	us-gaap_CommonUnitIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- 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

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_ScheduleOfCapitalizationEquityLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=amsc_MLVAndCoMember
Namespace Prefix:
Data Type:	na
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Period Type:

Stockholders' Equity - Additional Information (Detail) (USD $) In Thousands, except Share data in Millions, unless otherwise specified	0 Months Ended	3 Months Ended	9 Months Ended
	Nov. 13, 2014	Dec. 31, 2014	Dec. 31, 2014	Mar. 31, 2014	Nov. 15, 2013
Schedule Of Capitalization Equity [Line Items]
Common stock		$ 961us-gaap_CommonStockValue	$ 961us-gaap_CommonStockValue	$ 789us-gaap_CommonStockValue
Net proceeds from sale of common stock	9,100	9,100	9,114
Shares issued, price per share	$ 1.10us-gaap_SaleOfStockPricePerShare	$ 1.10us-gaap_SaleOfStockPricePerShare	$ 1.10us-gaap_SaleOfStockPricePerShare
Common stock units offered	9.1us-gaap_CommonUnitIssued
Number Of Warrants Issued To Purchase Common Stock	8.2
Warrant to purchase one share of common stock	90.00%
MLV & Co. LLC \| Atm Arrangement
Schedule Of Capitalization Equity [Line Items]
Commission on sale of common stock under the ATM					3.00%
Net proceeds from sale of common stock		1,000
Common stock, shares issued		0.8	0.8
Shares issued, price per share		$ 1.22	$ 1.22
MLV & Co. LLC \| Maximum \| Atm Arrangement
Schedule Of Capitalization Equity [Line Items]
Common stock					30,000