Subsequent Events	12 Months Ended
Mar. 31, 2012
Subsequent Events [Abstract]
Subsequent Events	18. Subsequent Events *Private Placement of 7% Senior Convertible Notes* On April 4, 2012, The Company entered into a Securities Purchase Agreement and completed a private placement of $25 million in 7% senior convertible notes (the "Notes") with Capital Ventures International, an affiliate of Heights Capital Management. The Notes have a conversion price of $4.85 per share, representing a premium of approximately 20% over AMSC's closing price on April 3, 2012. In addition, the buyers received warrants to purchase approximately 3.1 million additional shares of common stock exercisable at a strike price of $5.45 per share until October 4, 2017, subject to adjustment. The notes will amortize in monthly installments beginning four months from issuance and ending on October 4, 2014. Amortization payments are payable in cash or common stock at the option of the Company, subject to certain conditions. In addition, subject to certain conditions contained in the definitive agreements, on October 4, 2012, the Company may issue an additional $15 million aggregate principal amount of convertible notes and warrants to the same investor. *Senior Secured Term Loan* On June 5, 2012, the Company entered into a Loan and Security Agreement with Hercules Technology Growth Capital, under which the Company borrowed $10 million. The loan bears a floating rate of interest of 11% plus the percentage, if any, the prime rate exceeds 3.75%. The Company will make interest only payments beginning July 1, 2012 and continuing through November 1, 2012, after which the Company will repay the loan in equal monthly installments ending on December 1, 2014. The loan is secured by substantially all of the Company's existing and future assets. In addition, the lender received warrants to purchase approximately 139,000 shares of common stock, exercisable at a strike price of $3.59 per share until December 5, 2017. *Adverse Purchase Commitments* During the quarter ending June 30, 2012, the Company agreed to settle adverse purchase commitments with certain of its vendors. In conjunction with these settlements, the Company agreed to provide letters of credit and bank guarantees in the amount of approximately $9.0 million with expirations through January 31, 2013. The letters of credit and bank guarantees were secured with cash collateral of $8.5 million. As a result of these settlements, The Company will record a benefit of approximately $7.4 million in the quarter ending June 30, 2012.

18. Subsequent Events

Private Placement of 7% Senior Convertible Notes

On April 4, 2012, The Company entered into a Securities Purchase Agreement and completed a private placement of $25 million in 7% senior convertible notes (the "Notes") with Capital Ventures International, an affiliate of Heights Capital Management. The Notes have a conversion price of $4.85 per share, representing a premium of approximately 20% over AMSC's closing price on April 3, 2012. In addition, the buyers received warrants to purchase approximately 3.1 million additional shares of common stock exercisable at a strike price of $5.45 per share until October 4, 2017, subject to adjustment. The notes will amortize in monthly installments beginning four months from issuance and ending on October 4, 2014. Amortization payments are payable in cash or common stock at the option of the Company, subject to certain conditions.

In addition, subject to certain conditions contained in the definitive agreements, on October 4, 2012, the Company may issue an additional $15 million aggregate principal amount of convertible notes and warrants to the same investor.

Senior Secured Term Loan

On June 5, 2012, the Company entered into a Loan and Security Agreement with Hercules Technology Growth Capital, under which the Company borrowed $10 million. The loan bears a floating rate of interest of 11% plus the percentage, if any, the prime rate exceeds 3.75%. The Company will make interest only payments beginning July 1, 2012 and continuing through November 1, 2012, after which the Company will repay the loan in equal monthly installments ending on December 1, 2014. The loan is secured by substantially all of the Company's existing and future assets. In addition, the lender received warrants to purchase approximately 139,000 shares of common stock, exercisable at a strike price of $3.59 per share until December 5, 2017.

Adverse Purchase Commitments

During the quarter ending June 30, 2012, the Company agreed to settle adverse purchase commitments with certain of its vendors. In conjunction with these settlements, the Company agreed to provide letters of credit and bank guarantees in the amount of approximately $9.0 million with expirations through January 31, 2013. The letters of credit and bank guarantees were secured with cash collateral of $8.5 million. As a result of these settlements, The Company will record a benefit of approximately $7.4 million in the quarter ending June 30, 2012.