Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Sep. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 30,483	$ 30,534
Accumulated Amortization	(18,044)	(17,217)
Net Carrying Value	12,439	13,317
Supply Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	17,580	17,580
Accumulated Amortization	(7,811)	(7,225)
Net Carrying Value	9,769	10,355
Purchased Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	11,767	11,818
Accumulated Amortization	(9,301)	(9,121)
Net Carrying Value	2,466	2,697
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,136	1,136
Accumulated Amortization	(932)	(871)
Net Carrying Value	$ 204	$ 265