Description of Business	3 Months Ended
Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Business Overview EMCORE Corporation together with its subsidiaries (referred to herein as the “Company”, “we”, “our”, or “EMCORE”), was established in 1984 as a New Jersey corporation, designs and manufactures Indium Phosphide (InP) optical chips, components, subsystems and systems for the broadband and specialty fiber optics market. EMCORE is a provider of optical components, as well as complete end-to-end solutions for high-speed communications network infrastructures enabling systems and service providers to meet growing demand for bandwidth and connectivity. EMCORE's advanced optical technologies are designed for cable television (CATV), fiber-to-the-premises (FTTP) networks, telecommunications and data centers, satellite communications, aerospace and defense, wireless networks, and broadcast and professional audio/video systems. With its InP semiconductor wafer fabrication facility, EMCORE has fully vertically-integrated manufacturing capability and also provides contract design, foundry and component packaging services. We currently have one reporting segment: Fiber Optics. In addition to organic growth and development of our existing Fiber Optics market, we intend to pursue other strategies to enhance shareholder value, which may include acquisitions, investments in joint ventures, partnerships, and other strategic alternatives, such as dispositions, reorganizations, recapitalizations or other similar transactions, the repurchase of shares of our outstanding common stock or payment of dividends to our shareholders, and we may engage financial and other advisers to assist in these efforts. Accordingly, the Strategy and Alternatives Committee of the Board of Directors and our management may from time to time be engaged in evaluating potential strategic opportunities and may enter into definitive agreements with respect to such transactions or other strategic alternatives. Sale of Photovoltaics and Digital Products Businesses In the fiscal year ended September 30, 2015 EMCORE completed the sale of the company's Photovoltaics Business to SolAero Technologies Corporation (“SolAero”) pursuant to the Asset Purchase Agreement (the “Photovoltaics Agreement”) under which SolAero acquired substantially all of the assets, and assumed substantially all of the liabilities, primarily related to or used in connection with the Company's photovoltaics business, including EMCORE's subsidiaries EMCORE Solar Power, Inc. and EMCORE IRB Company, LLC (collectively, the “Photovoltaics Business” and, the sale of the Photovoltaics Business, the “Photovoltaics Asset Sale”) for $149.9 million in cash. In the fiscal year ended September 30, 2015 EMCORE completed the sale of the company's telecommunications business (the “Digital Products Business”) to NeoPhotonics Corporation, a Delaware corporation (“NeoPhotonics”) pursuant to the Asset Purchase Agreement (the “Digital Products Agreement”), under which NeoPhotonics acquired certain assets, and certain liabilities, related to the Company's Digital Products Business for an aggregate purchase price of $17.5 million. No Photovoltaics Business or Digital Products Business assets or liabilities that were sold remain on the consolidated balance sheet as of December 31, 2016 or September 30, 2016. The financial results of the Photovoltaics Business and the Digital Products Business are presented as “discontinued operations” on the condensed consolidated statements of operations and comprehensive income for the three months ended December 31, 2016 and 2015. See Note 3 - Discontinued Operations for additional information. The notes to our condensed consolidated financial statements relate to our continuing operations only, unless otherwise indicated. Interim Financial Statements The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim information, and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and notes required by U.S. GAAP for annual financial statements. In our opinion, the interim financial statements reflect all normal adjustments that are necessary to provide a fair presentation of the financial results for the interim periods presented. Operating results for interim periods are not necessarily indicative of results that may be expected for an entire fiscal year. The condensed consolidated balance sheet as of September 30, 2016 has been derived from the audited consolidated financial statements as of such date as adjusted for discontinued operations. See Note 3 - Discontinued Operations for additional information. For a more complete understanding of our business, financial position, operating results, cash flows, risk factors and other matters, please refer to our Annual Report on Form 10-K for the fiscal year ended September 30, 2016.

Description of Business

Business Overview

EMCORE Corporation together with its subsidiaries (referred to herein as the “Company”, “we”, “our”, or “EMCORE”), was established in 1984 as a New Jersey corporation, designs and manufactures Indium Phosphide (InP) optical chips, components, subsystems and systems for the broadband and specialty fiber optics market. EMCORE is a provider of optical components, as well as complete end-to-end solutions for high-speed communications network infrastructures enabling systems and service providers to meet growing demand for bandwidth and connectivity. EMCORE's advanced optical technologies are designed for cable television (CATV), fiber-to-the-premises (FTTP) networks, telecommunications and data centers, satellite communications, aerospace and defense, wireless networks, and broadcast and professional audio/video systems. With its InP semiconductor wafer fabrication facility, EMCORE has fully vertically-integrated manufacturing capability and also provides contract design, foundry and component packaging services.

We currently have one reporting segment: Fiber Optics. In addition to organic growth and development of our existing Fiber Optics market, we intend to pursue other strategies to enhance shareholder value, which may include acquisitions, investments in joint ventures, partnerships, and other strategic alternatives, such as dispositions, reorganizations, recapitalizations or other similar transactions, the repurchase of shares of our outstanding common stock or payment of dividends to our shareholders, and we may engage financial and other advisers to assist in these efforts. Accordingly, the Strategy and Alternatives Committee of the Board of Directors and our management may from time to time be engaged in evaluating potential strategic opportunities and may enter into definitive agreements with respect to such transactions or other strategic alternatives.

Sale of Photovoltaics and Digital Products Businesses

In the fiscal year ended September 30, 2015 EMCORE completed the sale of the company's Photovoltaics Business to SolAero Technologies Corporation (“SolAero”) pursuant to the Asset Purchase Agreement (the “Photovoltaics Agreement”) under which SolAero acquired substantially all of the assets, and assumed substantially all of the liabilities, primarily related to or used in connection with the Company's photovoltaics business, including EMCORE's subsidiaries EMCORE Solar Power, Inc. and EMCORE IRB Company, LLC (collectively, the “Photovoltaics Business” and, the sale of the Photovoltaics Business, the “Photovoltaics Asset Sale”) for $149.9 million in cash.

In the fiscal year ended September 30, 2015 EMCORE completed the sale of the company's telecommunications business (the “Digital Products Business”) to NeoPhotonics Corporation, a Delaware corporation (“NeoPhotonics”) pursuant to the Asset Purchase Agreement (the “Digital Products Agreement”), under which NeoPhotonics acquired certain assets, and certain liabilities, related to the Company's Digital Products Business for an aggregate purchase price of $17.5 million.

No Photovoltaics Business or Digital Products Business assets or liabilities that were sold remain on the consolidated balance sheet as of December 31, 2016 or September 30, 2016. The financial results of the Photovoltaics Business and the Digital Products Business are presented as “discontinued operations” on the condensed consolidated statements of operations and comprehensive income for the three months ended December 31, 2016 and 2015. See Note 3 - Discontinued Operations for additional information. The notes to our condensed consolidated financial statements relate to our continuing operations only, unless otherwise indicated.

Interim Financial Statements

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S. GAAP) for interim information, and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the Securities and Exchange Commission (SEC). Accordingly, they do not include all of the information and notes required by U.S. GAAP for annual financial statements. In our opinion, the interim financial statements reflect all normal adjustments that are necessary to provide a fair presentation of the financial results for the interim periods presented. Operating results for interim periods are not necessarily indicative of results that may be expected for an entire fiscal year. The condensed consolidated balance sheet as of September 30, 2016 has been derived from the audited consolidated financial statements as of such date as adjusted for discontinued operations. See Note 3 - Discontinued Operations for additional information. For a more complete understanding of our business, financial position, operating results, cash flows, risk factors and other matters, please refer to our Annual Report on Form 10-K for the fiscal year ended September 30, 2016.