Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 65,640	$ 47,770
Foreign tax credits	9,022	5,994
Capitalized research and development expense	41,720	51,237
Pension benefits	39,063	30,870
Deferred maintenance revenue	67,433	63,976
Stock-based compensation	16,744	18,045
Other reserves not currently deductible	25,258	19,343
Amortization of intangible assets	9,302	5,772
Other tax credits	30,982	31,263
Depreciation	3,157	3,077
Other	8,218	4,396
Gross deferred tax assets	316,539	281,743
Valuation allowance	(177,541)	(156,547)	(170,400)	(38,600)
Total deferred tax assets	138,998	125,196
Acquired intangible assets not deductible	(110,003)	(88,134)
Pension prepayments	(20,263)	(15,607)
Deferred revenue	(1,446)	(12,592)
Other	(4,484)	(4,463)
Total deferred tax liabilities	136,196	120,796
Net deferred tax assets	$ 2,802	$ 4,400