Composition of Certain Financial Statement Items Investment and Other Income, Net (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Investment Income, Net [Abstract]
Interest and dividend income	$ 30	$ 80	$ 135	$ 224
Net gains on marketable securities	117	315	183	296
Net gains on other investments	48	6	84	47
Net gains on deferred compensation plan assets	57	12	16	10
Impairment losses on other investments	(12)	(42)	(349)	(111)
Net gains (losses) on derivative investments	1	0	2	(10)
Equity in net losses of investees	(6)	(22)	(21)	(79)
Net losses on foreign currency transactions	(6)	(5)	(4)	0
Investment and other income, net	$ 229	$ 344	$ 46	$ 377

Net (losses) gains on deferred compensation plan assets

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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Amount of gain (loss) included in earnings for investments classified as other.

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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities.

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The aggregate amount of income from investments (for example, dividends) not considered a component of the entity's core operations.

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Amount of realized gain (loss) on investment in marketable security, excluding other-than-temporary impairment (OTTI).

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