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Significant Accounting Policies (Pass-Through Costs Included in Revenues) (Details) - USD ($) $ in Millions | 12 Months Ended
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Sep. 28, 2018 | Sep. 29, 2017 | Sep. 30, 2016
Accounting Policies [Abstract] |  |  |
Pass-through costs included in revenues | $ 3,058.6 | $ 2,539.3 | $ 2,489.9

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Period Type: | duration

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- References No definition available. + Details
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