Debt - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
Dec. 26, 2020	Dec. 28, 2019	Sep. 26, 2020
Debt Instrument [Line Items]
Commercial paper	$ 5,000		$ 4,996
Floating- and fixed-rate notes, aggregate principal amount	105,863		106,078
Interest cost on term debt	628	$ 757
Commercial paper
Debt Instrument [Line Items]
Commercial paper	$ 5,000		$ 5,000
Commercial paper, general maturity period (less than)	9 months
Commercial paper, weighted-average interest rate	0.10%		0.62%
Level 2
Debt Instrument [Line Items]
Floating- and fixed-rate notes, aggregate fair value	$ 117,200		$ 117,100

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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- Definition

Total interest costs incurred during the period and either capitalized or charged against earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

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- Definition

Weighted average interest rate of short-term debt outstanding calculated at point in time.

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