Fair Value Measurements (Schedule Of Available For Sale Securities) (Details) - USD ($) $ in Millions	Mar. 28, 2020	Sep. 28, 2019
U.S. treasury and agency
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost Basis	$ 56	$ 51
Fair Value	57	51
Unrealized Gain (Loss)	1	0
Corporate and asset-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost Basis	47	51
Fair Value	47	52
Unrealized Gain (Loss)	$ 0	$ 1

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

No definition available.

Name:	us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant