XML 53 R44.htm IDEA: XBRL DOCUMENT  v2.3.0.11

Business Segments (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Stock-based compensation expense	$ 3,466	$ 3,578
Maximum [Member]
Wind turbine power rating, megawatts	10
Unallocated Corporate Expenses [Member]
Stock-based compensation expense	$ 3,500	$ 3,500

X

- Definition

Wind turbine power rating, megawatts.

+ Details

Name:	amsc_WindTurbinePowerRatingMegawatts
Namespace Prefix:	amsc
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Represents the expense recognized during the period arising from share-based compensation arrangements (for example, shares of stock, 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 Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph 64
-Subparagraph b

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph A240
-Subparagraph g(1)

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration