Segment Information (Details) $ in Millions		3 Months Ended		6 Months Ended
		Mar. 29, 2026 USD ($)	Mar. 30, 2025 USD ($)	Mar. 29, 2026 USD ($) numberOfBusinesses	Mar. 30, 2025 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | numberOfBusinesses				3
Revenues		$ 10,599	$ 10,979	$ 22,851	$ 22,649
Cost of revenues		(4,900)	(4,937)	(10,468)	(10,098)
Research and development expenses		(2,463)	(2,216)	(4,915)	(4,446)
Selling, general and administrative expenses		(898)	(706)	(1,763)	(1,430)
Other		(29)	0	(29)	0
Interest expense		(171)	(163)	(341)	(326)
Costs and Expenses		8,290	7,859	17,175	15,974
Investment and other income, net		94	148	444	391
EBT		2,232	3,105	5,779	6,740
Reconciling Items
Segment Reporting Information [Line Items]
Cost of revenues		(95)	(60)	(178)	(119)
Research and development expenses		(616)	(558)	(1,314)	(1,156)
Selling, general and administrative expenses		(274)	(184)	(573)	(372)
Other		(29)	0	(29)	0
Interest expense		(171)	(163)	(341)	(326)
Investment and other (expense) income, net		109	138	278	358
Reconciling Items | Licensing Agreements
Segment Reporting Information [Line Items]
Revenues		0	143	0	143
Operating Segments
Segment Reporting Information [Line Items]
Revenues		10,458	10,788	22,663	22,407
EBT		3,429	3,796	8,140	8,218
QCT | Operating Segments
Segment Reporting Information [Line Items]
Revenues		9,076	9,469	19,689	19,553
Revenues		9,076	9,469	19,689	19,553
Cost of revenues		4,700	4,834	10,145	9,898
Operating Expenses		1,911	1,778	3,777	3,552
EBT		2,465	2,857	5,767	6,103
QTL | Operating Segments
Segment Reporting Information [Line Items]
Revenues		1,382	1,319	2,974	2,854
Costs and Expenses	[1]	388	390	750	768
EBT		994	929	2,224	2,086
QSI | Operating Segments
Segment Reporting Information [Line Items]
Revenues		0	0	0	0
Operating Expenses		3	3	5	6
Investment and other income, net		(27)	13	154	35
EBT		(30)	10	149	29
Other Operating Segment | Reconciling Items
Segment Reporting Information [Line Items]
Revenues		141	48	188	99
EBT		$ (121)	$ (7)	$ (204)	$ (6)

[1] Substantially all of QTL’s costs and expenses are comprised of operating expenses.