v2.4.0.8
Document and Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Mar. 31, 2015
May 22, 2015
Sep. 30, 2014
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Mar. 31, 2015    
Document Fiscal Year Focus 2014    
Document Fiscal Period Focus FY    
Entity Registrant Name AMERICAN SUPERCONDUCTOR CORP /DE/    
Trading Symbol AMSC    
Entity Central Index Key 0000880807    
Current Fiscal Year End Date --03-31    
Entity Filer Category Accelerated Filer    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Common Stock, Shares Outstanding   13,863,254  
Entity Public Float     $ 99.0