Financial Instruments - Cash, Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Millions	Mar. 28, 2026	Sep. 27, 2025
Marketable Securities [Line Items]
Cash, Cash Equivalents and Marketable Securities, Adjusted Cost	$ 149,418	$ 134,711
Cash Equivalents and Marketable Securities, Unrealized Gains	334	736
Cash Equivalents and Marketable Securities, Unrealized Losses	(3,157)	(3,027)
Cash, Cash Equivalents and Marketable Securities, Fair Value	146,595	132,420
Cash and Cash Equivalents	45,572	35,934
Current Marketable Securities	22,935	18,763
Non-Current Marketable Securities	78,088	77,723
Level 1
Marketable Securities [Line Items]
Marketable Securities, Equity, Adjusted Cost	7,409	5,951
Marketable Securities, Equity, Unrealized Gains	128	177
Marketable Securities, Equity, Unrealized Losses	(14)	(2)
Marketable Securities, Equity, Fair Value	7,523	6,126
Cash and Cash Equivalents	6,588	5,272
Current Marketable Securities	935	854
Non-Current Marketable Securities	0	0
Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	112,269	100,493
Marketable Securities, Debt, Unrealized Gains	206	559
Marketable Securities, Debt, Unrealized Losses	(3,143)	(3,025)
Marketable Securities, Debt, Fair Value	109,332	98,027
Cash and Cash Equivalents	9,244	2,395
Current Marketable Securities	22,000	17,909
Non-Current Marketable Securities	78,088	77,723
Cash
Marketable Securities [Line Items]
Cash	29,740	28,267
Cash and Cash Equivalents	29,740	28,267
Money market funds | Level 1
Marketable Securities [Line Items]
Marketable Securities, Equity, Adjusted Cost	6,588	5,272
Marketable Securities, Equity, Unrealized Gains	0	0
Marketable Securities, Equity, Unrealized Losses	0	0
Marketable Securities, Equity, Fair Value	6,588	5,272
Cash and Cash Equivalents	6,588	5,272
Current Marketable Securities	0	0
Non-Current Marketable Securities	0	0
Mutual funds | Level 1
Marketable Securities [Line Items]
Marketable Securities, Equity, Adjusted Cost	821	679
Marketable Securities, Equity, Unrealized Gains	128	177
Marketable Securities, Equity, Unrealized Losses	(14)	(2)
Marketable Securities, Equity, Fair Value	935	854
Cash and Cash Equivalents	0	0
Current Marketable Securities	935	854
Non-Current Marketable Securities	0	0
U.S. Treasury securities | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	18,650	16,074
Marketable Securities, Debt, Unrealized Gains	14	56
Marketable Securities, Debt, Unrealized Losses	(254)	(282)
Marketable Securities, Debt, Fair Value	18,410	15,848
Cash and Cash Equivalents	2,935	1,190
Current Marketable Securities	4,174	3,712
Non-Current Marketable Securities	11,301	10,946
U.S. agency securities | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	7,483	5,269
Marketable Securities, Debt, Unrealized Gains	0	0
Marketable Securities, Debt, Unrealized Losses	(112)	(149)
Marketable Securities, Debt, Fair Value	7,371	5,120
Cash and Cash Equivalents	2,923	251
Current Marketable Securities	2,470	2,456
Non-Current Marketable Securities	1,978	2,413
Non-U.S. government securities | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	5,906	6,586
Marketable Securities, Debt, Unrealized Gains	45	111
Marketable Securities, Debt, Unrealized Losses	(493)	(424)
Marketable Securities, Debt, Fair Value	5,458	6,273
Cash and Cash Equivalents	0	0
Current Marketable Securities	576	855
Non-Current Marketable Securities	4,882	5,418
Certificates of deposit and time deposits | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	3,263	917
Marketable Securities, Debt, Unrealized Gains	0	0
Marketable Securities, Debt, Unrealized Losses	0	0
Marketable Securities, Debt, Fair Value	3,263	917
Cash and Cash Equivalents	2,987	904
Current Marketable Securities	276	0
Non-Current Marketable Securities	0	13
Commercial paper | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	3,628	100
Marketable Securities, Debt, Unrealized Gains	0	0
Marketable Securities, Debt, Unrealized Losses	0	0
Marketable Securities, Debt, Fair Value	3,628	100
Cash and Cash Equivalents	399	50
Current Marketable Securities	3,229	50
Non-Current Marketable Securities	0	0
Corporate debt securities | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	48,111	47,210
Marketable Securities, Debt, Unrealized Gains	83	266
Marketable Securities, Debt, Unrealized Losses	(982)	(916)
Marketable Securities, Debt, Fair Value	47,212	46,560
Cash and Cash Equivalents	0	0
Current Marketable Securities	11,042	10,623
Non-Current Marketable Securities	36,170	35,937
Municipal securities | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	122	207
Marketable Securities, Debt, Unrealized Gains	0	0
Marketable Securities, Debt, Unrealized Losses	(1)	(2)
Marketable Securities, Debt, Fair Value	121	205
Cash and Cash Equivalents	0	0
Current Marketable Securities	95	119
Non-Current Marketable Securities	26	86
Mortgage- and asset-backed securities | Level 2
Marketable Securities [Line Items]
Marketable Securities, Debt, Adjusted Cost	25,106	24,130
Marketable Securities, Debt, Unrealized Gains	64	126
Marketable Securities, Debt, Unrealized Losses	(1,301)	(1,252)
Marketable Securities, Debt, Fair Value	23,869	23,004
Cash and Cash Equivalents	0	0
Current Marketable Securities	138	94
Non-Current Marketable Securities	$ 23,731	$ 22,910