Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands		Sep. 30, 2016		Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	[1]	$ 100,033		$ 71,533
Foreign tax credits	[1]	18,041		15,962
Capitalized research and development expense	[1]	22,504		31,690
Pension benefits	[1]	14,348		11,009
Deferred revenue	[1]	65,145		71,399
Stock-based compensation	[1]	19,846		16,777
Other reserves not currently deductible	[1]	25,993		21,940
Amortization of intangible assets	[1]	54,069		62,227
Other tax credits	[1]	41,381		37,270
Depreciation	[1]	3,002		3,465
Capital loss carryforward	[1]	8,019		8,040
Deferred Tax Asset, Deferred Interest	[1]	7,622		3,557
Other	[1]	14,778		6,559
Gross deferred tax assets	[1]	394,781		361,428
Valuation allowance		(235,503)	[1]	(198,168)	[1]	$ (177,500)	$ (156,500)
Total deferred tax assets	[1]	159,278		163,260
Acquired intangible assets not deductible	[1]	(78,663)		(124,401)
Pension prepayments	[1]	(542)		(395)
Deferred revenue	[1]	(2,039)		(3,110)
Other	[1]	(2,092)		(3,598)
Deferred Tax Liabilities, Gross	[1]	83,336		131,504
Net deferred tax assets	[1]	$ 75,942		$ 31,756

[1] (1) See Note B. Recent Accounting Pronouncements-Deferred Taxes regarding a change in the balance sheet classification of our deferred taxes.