Segment Data and Related Information (Schedule of Depreciation, Amortization, and Accretion Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Depreciation, amortization, and accretion expense	$ 2,095	$ 2,044	$ 4,163	$ 4,062
Fiber Optics
Segment Reporting Information [Line Items]
Depreciation, amortization, and accretion expense	1,456	1,384	2,940	2,666
Photovoltaics
Segment Reporting Information [Line Items]
Depreciation, amortization, and accretion expense	$ 639	$ 660	$ 1,223	$ 1,396