Intangible Assets (Schedule by Reporting Segment) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Assets	$ 22,907	$ 22,907
Accumulated Amortization	(20,748)	(19,479)
Total	2,159	3,428
Estimated Future Amortization Expense
Fiscal year ended September 30, 2014	1,017
Fiscal year ended September 30, 2015	555
Fiscal year ended September 30, 2016	554
Fiscal year ended September 30, 2017	33
Fiscal year ended September 30, 2018 and thereafter	0
Total	2,159	3,428
Fiber Optics
Finite-Lived Intangible Assets [Line Items]
Gross Assets	20,935	20,935
Accumulated Amortization	(18,967)	(17,890)
Total	1,968	3,045
Estimated Future Amortization Expense
Total	1,968	3,045
Fiber Optics | Core Technology
Finite-Lived Intangible Assets [Line Items]
Gross Assets	12,727	12,727
Accumulated Amortization	(11,822)	(11,150)
Total	905	1,577
Estimated Future Amortization Expense
Total	905	1,577
Fiber Optics | Customer Relations
Finite-Lived Intangible Assets [Line Items]
Gross Assets	3,511	3,511
Accumulated Amortization	(2,647)	(2,359)
Total	864	1,152
Estimated Future Amortization Expense
Total	864	1,152
Fiber Optics | Patents
Finite-Lived Intangible Assets [Line Items]
Gross Assets	4,697	4,697
Accumulated Amortization	(4,498)	(4,381)
Total	199	316
Estimated Future Amortization Expense
Total	199	316
Photovoltaics | Patents
Finite-Lived Intangible Assets [Line Items]
Gross Assets	1,972	1,972
Accumulated Amortization	(1,781)	(1,589)
Total	191	383
Estimated Future Amortization Expense
Total	$ 191	$ 383