Discontinued Operations (Narrative) (Details) - USD ($)			1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 22, 2015	Dec. 10, 2014	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Apr. 17, 2015	Jan. 02, 2015	Oct. 22, 2014	Sep. 17, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments to terminate lease agreement						$ 200,000
Gain on lease termination						310,000	$ 0
Gain on settlement						0	442,000	$ 0
Photovoltaics [Member] | Photovoltaics Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset purchase agreement, selling price		$ 150,000,000
Sumitomo Electric Industries, LTD [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on settlement						3,400,000
Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of venture	$ 700,000
Book value of outstanding receivables	$ 0
Incentive tax credits				$ 0		400,000	0
Payments to terminate lease agreement			$ 200,000
Gain on lease termination						300,000
Discontinued Operations, Disposed of by Sale [Member] | Digital Products Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset purchase agreement, selling price											$ 17,500,000
Gain on sale of business							2,000,000
Asset sale, promissory note, principal amount									$ 15,500,000	$ 1,500,000
Accrued interest on note receivable									$ 200,000
Discontinued Operations, Disposed of by Sale [Member] | Photovoltaics [Member] | Photovoltaics Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset purchase agreement, selling price												$ 150,000,000
Working capital adjustment							$ 100,000
Net assets sold		60,300,000
Transaction costs incurred in sale of business		$ 2,700,000
Gain on sale of business					$ 56,800,000
Discontinued Operations, Disposed of by Sale [Member] | Sumitomo Electric Industries, LTD [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Write off of loss accrual						400,000
Recognition of deferred gain						3,400,000
Gain on settlement						$ 3,800,000