Segment Data and Related Information (Statement of Operations Data) (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]
Operating income (loss)	$ (5,249)	$ 12,171	$ (7,489)	$ 15,017
Fiber Optics
Segment Reporting Information [Line Items]
Operating income (loss)	(7,320)	7,892	(13,891)	7,497
Photovoltaics
Segment Reporting Information [Line Items]
Operating income (loss)	$ 2,071	$ 4,279	$ 6,402	$ 7,520