Goodwill and Intangible Assets (Goodwill and Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	6 Months Ended
Mar. 30, 2019	Sep. 30, 2018
Goodwill (not amortized), Net Book Value	$ 1,229,541	$ 1,182,457
Intangible assets with finite lives (amortized), Gross Carrying Amount	779,265	766,199
Intangible assets with finite lives (amortized), Accumulated Amortization	586,893	565,997
Intangible assets with finite lives (amortized), Net Book Value	192,372	200,202
Intangible Assets, Net (Including Goodwill)	1,421,913	1,382,659
Purchased software
Intangible assets with finite lives (amortized), Gross Carrying Amount	378,842	362,679
Intangible assets with finite lives (amortized), Accumulated Amortization	265,881	254,059
Intangible assets with finite lives (amortized), Net Book Value	$ 112,961	108,620
Acquired finite-lived intangible asset, weighted average useful life	9 years
Capitalized software
Intangible assets with finite lives (amortized), Gross Carrying Amount	$ 22,877	22,877
Intangible assets with finite lives (amortized), Accumulated Amortization	22,877	22,877
Intangible assets with finite lives (amortized), Net Book Value	0	0
Customer lists and relationships
Intangible assets with finite lives (amortized), Gross Carrying Amount	354,600	357,586
Intangible assets with finite lives (amortized), Accumulated Amortization	279,139	270,272
Intangible assets with finite lives (amortized), Net Book Value	$ 75,461	87,314
Acquired finite-lived intangible asset, weighted average useful life	10 years
Trademarks and trade names
Intangible assets with finite lives (amortized), Gross Carrying Amount	$ 18,994	19,054
Intangible assets with finite lives (amortized), Accumulated Amortization	15,044	14,786
Intangible assets with finite lives (amortized), Net Book Value	$ 3,950	4,268
Acquired finite-lived intangible asset, weighted average useful life	11 years
Other
Intangible assets with finite lives (amortized), Gross Carrying Amount	$ 3,952	4,003
Intangible assets with finite lives (amortized), Accumulated Amortization	3,952	4,003
Intangible assets with finite lives (amortized), Net Book Value	$ 0	$ 0

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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- Definition

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.

+ References

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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- Definition

Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance.

+ References

No definition available.

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