Shareholder Rights Plan	12 Months Ended
Sep. 30, 2017
Stockholders' Equity Note [Abstract]
Shareholder Rights Plan	On December 15, 2008, Amtech and Computershare Trust Company, N.A., as Rights Agent (the “Rights Agent”), entered into an Amended and Restated Rights Agreement (the “Restated Rights Agreement”) which amended and restated the terms governing the previously authorized shareholder rights (each a “Right”) to purchase fractional shares of our Series A Participating Preferred Stock (“Series A Preferred”) currently attached to each of our outstanding Common Shares, par value $0.01 per share (“Common Shares”). As amended, each Right entitles the registered holder to purchase from us one one-thousandth of a share of Series A Preferred at an exercise price of $51.60 (the “Exercise Price”), subject to adjustment. The rights will expire 10 years after issuance and will be exercisable if (a) a person or group becomes the beneficial owner of 15% or more of our common stock or (b) a person or group commences a tender or exchange offer that would result in the offeror beneficially owning 15% or more of our common stock. The Final Expiration Date (as defined in the Restated Rights Agreement) is December 14, 2018. On October 1, 2015, we entered into a Second Amended and Restated Rights Agreement (the “Second Restated Rights Agreement”) with Computershare Trust Company, N.A., which expands the definition of Exempted Person to include any person that the Board, in its sole and absolute discretion, exempts from becoming an Acquiring Person under the Second Restated Rights Agreement. A person deemed an Exempted Person under the Second Restated Rights Agreement cannot trigger any of the Rights provided therein so long as such Exempted Person complies with the terms and conditions by which the Board approved such exemption from the Restated Rights Agreement. As previously disclosed, on October 8, 2015, we entered into a Letter Agreement (the “Agreement”) by and between Amtech and certain shareholders of Amtech who jointly file (the “Joint Filers”) under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The Agreement permits the Joint Filers, pursuant to the Restated Rights Agreement, to individually acquire shares of common stock of Amtech that would, in the aggregate, bring the Joint Filers’ collective ownership to no more than 19.9% of our issued and outstanding common stock at any time. In the event the Joint Filers’ collective ownership at any time exceeds 19.9% of our issued and outstanding shares of common stock, we are entitled to specific performance and all other remedies entitled to us at law or equity, among others. The Board approved the Agreement and transactions contemplated thereunder, and has the sole authority to terminate the Agreement at any time.

On December 15, 2008, Amtech and Computershare Trust Company, N.A., as Rights Agent (the “Rights Agent”), entered into an Amended and Restated Rights Agreement (the “Restated Rights Agreement”) which amended and restated the terms governing the previously authorized shareholder rights (each a “Right”) to purchase fractional shares of our Series A Participating Preferred Stock (“Series A Preferred”) currently attached to each of our outstanding Common Shares, par value $0.01 per share (“Common Shares”). As amended, each Right entitles the registered holder to purchase from us one one-thousandth of a share of Series A Preferred at an exercise price of $51.60 (the “Exercise Price”), subject to adjustment. The rights will expire 10 years after issuance and will be exercisable if (a) a person or group becomes the beneficial owner of 15% or more of our common stock or (b) a person or group commences a tender or exchange offer that would result in the offeror beneficially owning 15% or more of our common stock. The Final Expiration Date (as defined in the Restated Rights Agreement) is December 14, 2018.

On October 1, 2015, we entered into a Second Amended and Restated Rights Agreement (the “Second Restated Rights Agreement”) with Computershare Trust Company, N.A., which expands the definition of Exempted Person to include any person that the Board, in its sole and absolute discretion, exempts from becoming an Acquiring Person under the Second Restated Rights Agreement. A person deemed an Exempted Person under the Second Restated Rights Agreement cannot trigger any of the Rights provided therein so long as such Exempted Person complies with the terms and conditions by which the Board approved such exemption from the Restated Rights Agreement.

As previously disclosed, on October 8, 2015, we entered into a Letter Agreement (the “Agreement”) by and between Amtech and certain shareholders of Amtech who jointly file (the “Joint Filers”) under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The Agreement permits the Joint Filers, pursuant to the Restated Rights Agreement, to individually acquire shares of common stock of Amtech that would, in the aggregate, bring the Joint Filers’ collective ownership to no more than 19.9% of our issued and outstanding common stock at any time. In the event the Joint Filers’ collective ownership at any time exceeds 19.9% of our issued and outstanding shares of common stock, we are entitled to specific performance and all other remedies entitled to us at law or equity, among others. The Board approved the Agreement and transactions contemplated thereunder, and has the sole authority to terminate the Agreement at any time.