XML 26 R67.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Warrants And Derivative Liabilities (Schedule Of The Fair Value Of The Warrants Using The Black-Scholes Option Pricing Model - Securities Agreement) (Details) (USD $) In Millions, unless otherwise specified | 0 Months Ended | 3 Months Ended
--- | --- | ---
Apr. 04, 2012 | Mar. 31, 2013 | Dec. 31, 2012 | Sep. 30, 2012 | Jun. 30, 2012
Derivative [Line Items] |  |  |  |  |
Risk-free interest rate | 0.44% | 0.20% | 0.23% | 0.23% | 0.33%
Expected annual dividend yield | 15.00% | 16.50% | 16.50% | 15.00% | 16.00%
Expected volatility | 75.00% | 66.90% | 73.50% | 70.00% | 71.00%
Term (years) | 2 years 6 months | 1 year 6 months 4 days | 1 year 9 months 4 days | 2 years 4 days | 2 years 3 months 11 days
Securities Purchase Agreement [Member] |  |  |  |  |
Derivative [Line Items] |  |  |  |  |
Risk-free interest rate | 1.19% | 0.67% | 0.75% | 0.63% | 0.77%
Expected annual dividend yield | 0.00% | 0.00% | 0.00% | 0.00% | 0.00%
Expected volatility | 80.00% | 71.70% | 80.60% | 80.90% | 80.80%
Term (years) | 5 years 6 months | 4 years 6 months 4 days | 4 years 9 months 4 days | 5 years 4 days | 5 years 3 months 11 days
Fair Value | 7.0 | 3.4 | 4.4 | 7.1 | 8.6

X
- Definition Warrant Instruments, Fair Value Disclosure. + References No definition available. + Details
Name: | amsc_WarrantInstrumentsFairValueDisclosure
Namespace Prefix: | amsc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedDividendRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock 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=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedVolatilityRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Risk-free interest rate assumption used in valuing an instrument. + 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=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsRiskFreeInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration