Description of Business (Liquidity and Capital Resources) (Details) - USD ($) $ / shares in Units, shares in Millions		1 Months Ended	3 Months Ended								12 Months Ended
	Jun. 15, 2015	Jun. 30, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014	Jul. 05, 2016	Dec. 10, 2014	Sep. 30, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Shares acquired (in shares)	6.9
Average cost per share (in usd per share)	$ 6.55
Repurchases of common stock	$ 45,000,000										$ 0	$ 45,650,000	$ 0
Repurchase costs	$ 700,000
Cash and cash equivalents			$ 63,905,000				$ 111,885,000				63,905,000	111,885,000	20,687,000			$ 16,104,000
Working capital			93,000,000								93,000,000
Net income			$ 1,996,000	$ 1,301,000	$ 3,982,000	$ 987,000	$ 1,480,000	$ 2,440,000	$ 3,052,000	$ 56,128,000	8,266,000	$ 63,100,000	$ 4,852,000
Dividends payable (in usd per share)														$ 1.50
Dividends payable														$ 39,200,000
Photovoltaics Business [Member] | Photovoltaics [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset purchase agreement, selling price															$ 150,000,000
Sixth Amendment [Member] | Revolving Credit Facility [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Line of credit facility, maximum borrowing capacity															$ 15,000,000.00
Sumitomo Electric Industries, LTD [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Recovery of fees and costs from SEI				$ 2,600,000
Settled Litigation [Member] | Sumitomo Electric Industries, LTD [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Recovery of fees and costs from SEI											$ 2,600,000
Loss contingency, proceeds		$ 1,900,000