Stockholders' Equity	3 Months Ended
Jun. 30, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Equity Offerings On May 5, 2017, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc., as representative of several underwriters named therein, relating to the issuance and sale (the "Offering") of 4.0 million shares of the Company's common stock at a public offering price of $4.00 per share. The net proceeds to the Company from the Offering were approximately $14.7 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. The Offering closed on May 10, 2017. In addition, the Company granted the underwriters a 30-day option (the “Option”) to purchase up to an additional 600,000 shares of common stock at the public offering price. On May 24, 2017, the underwriters notified the Company that they had exercised in full, their Option. The net proceeds to the Company from the Option were approximately $2.3 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. The total net proceeds to the Company from the Offering and the Option were approximately $17.0 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. The Option closed on May 26, 2017. ATM Arrangement On January 27, 2017, the Company entered into an At Market Issuance Sales Agreement ("ATM"), pursuant to which, the Company could, at its discretion, sell up to $10.0 million of the Company’s common stock through its sales agent, FBR Capital Markets & Co. ("FBR"). Sales of common stock made under the ATM were made pursuant to the prospectus supplement dated January 27, 2017, which supplements the prospectus dated October 1, 2014, included in the shelf registration statement that AMSC filed with the SEC on September 19, 2014. During the year ended March 31, 2017, the Company received net proceeds of $2.5 million, from sales of approximately 379,693 shares of its common stock at an average sales price of approximately $6.79 per share under the ATM. No sales of the Company's common stock were made under the ATM after March 31, 2017. On May 4, 2017, the Company provided to FBR a notice of termination of the ATM.

Stockholders’ Equity

Equity Offerings

On May 5, 2017, the Company entered into an underwriting agreement with Oppenheimer & Co. Inc., as representative of several underwriters named therein, relating to the issuance and sale (the "Offering") of 4.0 million shares of the Company's common stock at a public offering price of $4.00 per share. The net proceeds to the Company from the Offering were approximately $14.7 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. The Offering closed on May 10, 2017. In addition, the Company granted the underwriters a 30-day option (the “Option”) to purchase up to an additional 600,000 shares of common stock at the public offering price. On May 24, 2017, the underwriters notified the Company that they had exercised in full, their Option. The net proceeds to the Company from the Option were approximately $2.3 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. The total net proceeds to the Company from the Offering and the Option were approximately $17.0 million, after deducting underwriting discounts and commissions and offering expenses payable by the Company. The Option closed on May 26, 2017.

ATM Arrangement

On January 27, 2017, the Company entered into an At Market Issuance Sales Agreement ("ATM"), pursuant to which, the Company could, at its discretion, sell up to $10.0 million of the Company’s common stock through its sales agent, FBR Capital Markets & Co. ("FBR"). Sales of common stock made under the ATM were made pursuant to the prospectus supplement dated January 27, 2017, which supplements the prospectus dated October 1, 2014, included in the shelf registration statement that AMSC filed with the SEC on September 19, 2014.

During the year ended March 31, 2017, the Company received net proceeds of $2.5 million, from sales of approximately 379,693 shares of its common stock at an average sales price of approximately $6.79 per share under the ATM. No sales of the Company's common stock were made under the ATM after March 31, 2017. On May 4, 2017, the Company provided to FBR a notice of termination of the ATM.