Fair Value Measurement (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other than Temporary Impairments, Recognized in Earnings	$ 0	$ 0	$ 0	$ 0
Other than Temporary Impairment Losses, Deferred in OCI	$ 0	$ 0	$ 0	$ 0
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short Term Investment Maturity Period			12 months
Available For Sale Securities Debt Maturity Period			40 years