Goodwill	12 Months Ended
Sep. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill Impairment Testing - Fiscal 2012: As of September 30, 2012, we performed an annual goodwill impairment test and reviewed the qualitative factors as described in ASU No. 2011-08. We determined that it was not more likely than not that the fair value of our Photovoltaics reporting unit was less than its carrying amount. Impairment Testing - Fiscal 2013: As of September 30, 2013, we performed an annual goodwill impairment test and reviewed the qualitative factors as described in ASU No. 2011-08. Due to the length of time that has elapsed and changes in the underlying assumptions used in our prior quantitative impairment test, we determined to skip the qualitative assessment and perform a quantitative, step one, assessment of possible impairment based on the estimated fair value of the reporting unit. We determined based on that analysis that goodwill related to our photovoltaics reporting unit was not impaired. Impairment Testing - Fiscal 2014: On September 17, 2014, EMCORE entered into an Asset Purchase Agreement with Photon to sell the Photovoltaics Business for $150.0 million in cash, subject to working capital adjustments pursuant to the Photovoltaics Agreement. As of September 30, 2014, management performed the Step 1 test, which compares the fair value of the reporting unit with its carrying value, including goodwill. As of September 30, 2014, no impairment existed. On December 10, 2014, EMCORE completed the sale of its Photovoltaics Business to Photon. See Note 18 - Subsequent Events for additional information. We will continue to monitor any changes in circumstances or triggering events that might indicate impairment of our goodwill. If there is a significant erosion of the Company’s market capitalization or the Photovoltaics reporting unit is unable to achieve its projected cash flows, we may be required to perform additional impairment tests. The outcome of these additional tests may result in the recording of goodwill impairment charges.

Goodwill

Impairment Testing - Fiscal 2012:

As of September 30, 2012, we performed an annual goodwill impairment test and reviewed the qualitative factors as described in ASU No. 2011-08. We determined that it was not more likely than not that the fair value of our Photovoltaics reporting unit was less than its carrying amount.

Impairment Testing - Fiscal 2013:

As of September 30, 2013, we performed an annual goodwill impairment test and reviewed the qualitative factors as described in ASU No. 2011-08. Due to the length of time that has elapsed and changes in the underlying assumptions used in our prior quantitative impairment test, we determined to skip the qualitative assessment and perform a quantitative, step one, assessment of possible impairment based on the estimated fair value of the reporting unit. We determined based on that analysis that goodwill related to our photovoltaics reporting unit was not impaired.

Impairment Testing - Fiscal 2014:

On September 17, 2014, EMCORE entered into an Asset Purchase Agreement with Photon to sell the Photovoltaics Business for $150.0 million in cash, subject to working capital adjustments pursuant to the Photovoltaics Agreement. As of September 30, 2014, management performed the Step 1 test, which compares the fair value of the reporting unit with its carrying value, including goodwill. As of September 30, 2014, no impairment existed. On December 10, 2014, EMCORE completed the sale of its Photovoltaics Business to Photon. See Note 18 - Subsequent Events for additional information.

We will continue to monitor any changes in circumstances or triggering events that might indicate impairment of our goodwill. If there is a significant erosion of the Company’s market capitalization or the Photovoltaics reporting unit is unable to achieve its projected cash flows, we may be required to perform additional impairment tests. The outcome of these additional tests may result in the recording of goodwill impairment charges.