Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) (USD $) In Thousands	Sep. 30, 2011	Sep. 30, 2010
Income Taxes [Abstract]
Net operating loss carryforwards	$ 29,785	$ 27,962
Foreign tax credits	5,403	12,315
Capitalized research and development expense	66,957	44,162
Pension benefits	25,431	22,327
Deferred maintenance revenue	13,786
Stock-based compensation	15,723	15,624
Restructuring reserves not currently deductible	989	803
Accrual for litigation	17,893	19,410
Other reserves not currently deductible	14,739	14,698
Amortization of intangible assets	7,552	7,061
Other tax credits	20,432	23,863
Depreciation	4,816	5,048
Other	6,859	4,085
Gross deferred tax assets	230,365	197,358
Valuation allowance	(38,600)	(40,545)
Total deferred tax assets	191,765	156,813
Acquired intangible assets not deductible	(58,303)	(34,585)
Pension prepayments	(10,957)	(12,030)
Unremitted earnings of foreign subsidiary		(6,520)
Other	(649)	(191)
Total deferred tax liabilities	(69,909)	(53,326)
Net deferred tax assets	$ 121,856	$ 103,487