Goodwill and Intangible Assets (Narrative) (Details) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Mar. 31, 2018 USD ($) Segment	Dec. 30, 2017 Segment	Mar. 31, 2018 USD ($)	Sep. 30, 2017 USD ($) Segment
Number of operating segments \| Segment	2	2		3
Number of reportable segments \| Segment	2			3
Intangible Assets, Net (Including Goodwill)	$ 1,421,633		$ 1,421,633	$ 1,440,680
Foreign currency translation adjustment			4,481
Goodwill	1,191,603		1,191,603	1,182,772
Professional Services
Intangible Assets, Net (Including Goodwill)	30,600		30,600	30,600
Foreign currency translation adjustment			113
Goodwill	29,968		29,968	29,855
Software Products
Intangible Assets, Net (Including Goodwill)	1,391,000		1,391,000	1,410,000
Foreign currency translation adjustment			4,368
Goodwill	$ 1,161,635		$ 1,161,635	$ 1,152,917

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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