Goodwill and Intangible Assets (Goodwill and Acquired Intangible Assets) (Details) - USD ($) $ in Thousands		6 Months Ended
		Apr. 02, 2016	Sep. 30, 2015
Goodwill (not amortized), Net Book Value		$ 1,172,772	$ 1,069,041
Intangible assets with finite lives (amortized), Gross Carrying Amount	[1]	757,344	679,552
Intangible assets with finite lives (amortized), Accumulated Amortization	[1]	418,700	388,251
Intangible assets with finite lives (amortized), Net Book Value	[1]	338,644	291,301
Intangible Assets, Net (Including Goodwill)		1,511,416	1,360,342
Purchased Software
Intangible assets with finite lives (amortized), Gross Carrying Amount		354,482	284,257
Intangible assets with finite lives (amortized), Accumulated Amortization		187,446	174,887
Intangible assets with finite lives (amortized), Net Book Value	[1]	$ 167,036	109,370
Acquired finite-lived intangible asset, weighted average useful life		7 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	[1]	0	0
Customer Lists and Relationships
Intangible assets with finite lives (amortized), Gross Carrying Amount		356,883	349,938
Intangible assets with finite lives (amortized), Accumulated Amortization		191,439	174,017
Intangible assets with finite lives (amortized), Net Book Value	[1]	$ 165,444	175,921
Acquired finite-lived intangible asset, weighted average useful life		10 years
Trademarks and Trade Names
Intangible assets with finite lives (amortized), Gross Carrying Amount		$ 19,128	18,534
Intangible assets with finite lives (amortized), Accumulated Amortization		13,087	12,759
Intangible assets with finite lives (amortized), Net Book Value	[1]	$ 6,041	5,775
Acquired finite-lived intangible asset, weighted average useful life		9 years
Other
Intangible assets with finite lives (amortized), Gross Carrying Amount		$ 3,974	3,946
Intangible assets with finite lives (amortized), Accumulated Amortization		3,851	3,711
Intangible assets with finite lives (amortized), Net Book Value	[1]	$ 123	$ 235
Acquired finite-lived intangible asset, weighted average useful life		3 years

[1] The weighted average useful lives of purchased software, customer lists and relationships, trademarks and trade names and other intangible assets with a remaining net book value are 7 years, 10 years, 9 years, and 3 years, respectively.