v3.8.0.1
Document and Entity Information - shares
9 Months Ended
Dec. 31, 2017
Feb. 01, 2018
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Dec. 31, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q3  
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 Common Stock, Shares Outstanding   20,936,769