Goodwill and Acquired Intangible Assets (Amortization Of Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquired intangible assets	$ 20,303	$ 18,319	$ 15,605
Cost of license revenue	15,819	15,393	18,367
Total amortization expense	$ 36,122	$ 33,712	$ 33,972

Aggregate amount of intangible asset amortization recognized as expense during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16323-109275

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration