Goodwill and Intangible Assets (Goodwill and Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 28, 2019	Sep. 30, 2019
Goodwill (not amortized)	$ 1,606,050	$ 1,238,179
Intangible assets with finite lives (amortized), Gross Carrying Amount	892,248	778,968
Intangible assets with finite lives (amortized), Accumulated Amortization	626,239	609,019
Intangible assets with finite lives (amortized), Net Book Value	266,009	169,949
Intangible Assets, Net (Including Goodwill)	1,872,059	1,408,128
Purchased software
Intangible assets with finite lives (amortized), Gross Carrying Amount	422,922	377,359
Intangible assets with finite lives (amortized), Accumulated Amortization	286,307	278,144
Intangible assets with finite lives (amortized), Net Book Value	136,615	99,215
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	419,906	355,931
Intangible assets with finite lives (amortized), Accumulated Amortization	297,574	288,828
Intangible assets with finite lives (amortized), Net Book Value	122,332	67,103
Trademarks and trade names
Intangible assets with finite lives (amortized), Gross Carrying Amount	22,597	18,891
Intangible assets with finite lives (amortized), Accumulated Amortization	15,535	15,260
Intangible assets with finite lives (amortized), Net Book Value	7,062	3,631
Other
Intangible assets with finite lives (amortized), Gross Carrying Amount	3,946	3,910
Intangible assets with finite lives (amortized), Accumulated Amortization	3,946	3,910
Intangible assets with finite lives (amortized), Net Book Value	$ 0	$ 0