Description of Business (Sale of Fiber Optics-related Assets) (Details) - USD ($) $ in Thousands		12 Months Ended
	May. 07, 2012	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	May. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of assets		$ 0	$ 0	$ 1,150
Deferred gain associated with sale of assets		3,400	3,400
Fees billed during the period			$ 3,300	2,800
Sales price adjustment					$ 500
Expenses incurred in association with sale					$ 600
Sumitomo Electric Industries, LTD [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of assets	$ 2,800
Indemnification associated with sale of assets	$ 3,400
Indemnification period	2 years
Proceeds from sale of assets	$ 13,100
Cash held in escrow	$ 2,600
Reduction of purchase price				$ 1,100
Sumitomo Electric Industries, LTD [Member] | Indemnification Obligation [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Deferred gain associated with sale of assets		$ 3,400