XML 27 R61.htm IDEA: XBRL DOCUMENT v2.4.1.9

Business Segments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014 Segment	Dec. 31, 2013
Segment Reporting Information [Line Items]
Number of reportable business segments			2us-gaap_NumberOfReportableSegments
Stock-based compensation expense	$ 1,521us-gaap_AllocatedShareBasedCompensationExpense	$ 3,040us-gaap_AllocatedShareBasedCompensationExpense	$ 4,620us-gaap_AllocatedShareBasedCompensationExpense	$ 7,328us-gaap_AllocatedShareBasedCompensationExpense
Restructuring and impairments	$ 507us-gaap_RestructuringSettlementAndImpairmentProvisions	$ 108us-gaap_RestructuringSettlementAndImpairmentProvisions	$ 5,416us-gaap_RestructuringSettlementAndImpairmentProvisions	$ 872us-gaap_RestructuringSettlementAndImpairmentProvisions
Minimum
Segment Reporting Information [Line Items]
Megawatts of drive trains and power ratings			2amsc_BusinessSegmentsPowerOfWindTurbines / us-gaap_RangeAxis = us-gaap_MinimumMember

X

- Definition

Business segments power of wind turbines.

+ References

No definition available.

+ Details

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Namespace Prefix:	amsc_
Data Type:	num:powerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 14.F)

-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The aggregate amount provided for estimated restructuring charges, remediation costs, and asset impairment loss during an accounting period. Generally, these items are either unusual or infrequent, but not both (in which case they would be extraordinary items).

+ 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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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- Details

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