Segment Data and Related Information (Schedule of Stock-based Compensation 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]
Stock-based compensation expense	$ 1,104	$ 1,051	$ 2,239	$ 2,133
Fiber Optics
Segment Reporting Information [Line Items]
Stock-based compensation expense	674	702	1,429	1,428
Photovoltaics
Segment Reporting Information [Line Items]
Stock-based compensation expense	$ 430	$ 349	$ 810	$ 705