Subsequent Events	9 Months Ended
Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On February 1, 2018, ASC Devens, LLC (the “Seller”), a wholly owned subsidiary of American Superconductor Corporation (the “Company”), entered into a Purchase and Sale Agreement (the “PSA”) with 64 Jackson LLC (the “Purchaser”) and Stewart Title Guaranty Company (“Escrow Agent”), pursuant to which the Seller has agreed to sell to the Purchaser certain real property located at 64 Jackson Road, Devens, Massachusetts, as described in the PSA, including the building that has served as the Company’s headquarters (collectively, the “Property”), in exchange for total consideration of $23.0 million, which is composed of (i) cash consideration of $17.0 million, and (ii) a $6.0 million subordinated secured commercial promissory note payable to the Seller (the “Seller Note”) at an interest rate equal to the short-term applicable federal rate then in effect at closing (the “Transaction”). The cash consideration includes a deposit of $500,000 (the “First Deposit”), which the Purchaser has agreed to deposit with the Escrow Agent within three business days after the execution of the PSA, and a second deposit (together with the First Deposit, the “Deposit”) of $500,000, which the Purchaser has agreed to deposit with the Escrow Agent on February 15, 2018, provided that the Seller has not terminated the PSA by that date. The PSA contains customary representations, warranties and covenants of the Seller and the Purchaser. The Transaction is anticipated to close on March 30, 2018. Pursuant to the PSA, at closing, the Escrow Agent has agreed to deliver the Deposit to the Seller, and Purchaser has agreed to deliver the remaining cash consideration and the Seller Note to the Seller. The closing of the Transaction is not contingent on any due diligence investigations (other than title), permitting, or financing, however, there is no guarantee that the Transaction will close in the timeframe the Company expects, or at all. According to the Seller Note, the form of which is attached as Exhibit B to the PSA, $3,000,000 in principal, together with all accrued interest, is due and payable to the Seller on March 31, 2019, and $3,000,000 in principal, together with all accrued interest, is due and payable to the Seller on March 31, 2020, provided that, if the Purchaser sells the Property, all unpaid principal and accrued interest must be repaid in full. The Company has performed an evaluation of subsequent events through the time of filing this Quarterly Report on Form 10-Q with the SEC and has determined that other than those disclosed above, there are no such events to report.

Subsequent Events

On February 1, 2018, ASC Devens, LLC (the “Seller”), a wholly owned subsidiary of American Superconductor Corporation (the “Company”), entered into a Purchase and Sale Agreement (the “PSA”) with 64 Jackson LLC (the “Purchaser”) and Stewart Title Guaranty Company (“Escrow Agent”), pursuant to which the Seller has agreed to sell to the Purchaser certain real property located at 64 Jackson Road, Devens, Massachusetts, as described in the PSA, including the building that has served as the Company’s headquarters (collectively, the “Property”), in exchange for total consideration of $23.0 million, which is composed of (i) cash consideration of $17.0 million, and (ii) a $6.0 million subordinated secured commercial promissory note payable to the Seller (the “Seller Note”) at an interest rate equal to the short-term applicable federal rate then in effect at closing (the “Transaction”). The cash consideration includes a deposit of $500,000 (the “First Deposit”), which the Purchaser has agreed to deposit with the Escrow Agent within three business days after the execution of the PSA, and a second deposit (together with the First Deposit, the “Deposit”) of $500,000, which the Purchaser has agreed to deposit with the Escrow Agent on February 15, 2018, provided that the Seller has not terminated the PSA by that date. The PSA contains customary representations, warranties and covenants of the Seller and the Purchaser. The Transaction is anticipated to close on March 30, 2018. Pursuant to the PSA, at closing, the Escrow Agent has agreed to deliver the Deposit to the Seller, and Purchaser has agreed to deliver the remaining cash consideration and the Seller Note to the Seller. The closing of the Transaction is not contingent on any due diligence investigations (other than title), permitting, or financing, however, there is no guarantee that the Transaction will close in the timeframe the Company expects, or at all.

According to the Seller Note, the form of which is attached as Exhibit B to the PSA, $3,000,000 in principal, together with all accrued interest, is due and payable to the Seller on March 31, 2019, and $3,000,000 in principal, together with all accrued interest, is due and payable to the Seller on March 31, 2020, provided that, if the Purchaser sells the Property, all unpaid principal and accrued interest must be repaid in full.

The Company has performed an evaluation of subsequent events through the time of filing this Quarterly Report on Form 10-Q with the SEC and has determined that other than those disclosed above, there are no such events to report.