Segment Data and Related Information - Schedule of Segment Revenue (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 43,738	$ 44,582	$ 42,247	$ 44,211	$ 43,091	$ 33,473	$ 42,277	$ 49,306	$ 174,778	$ 168,147	$ 163,781
Fiber Optics
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									101,552	96,977	96,153
Photovoltaics
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									$ 73,226	$ 71,170	$ 67,628