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Goodwill and Intangible Assets (Changes in Goodwill by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 27, 2024	Sep. 29, 2023	Sep. 27, 2024	Sep. 29, 2023	Dec. 29, 2023
Goodwill [Roll Forward]
Beginning balance, goodwill			$ 6,112	$ 6,696	$ 6,696
Goodwill impairment	$ 0	$ (599)	0	(599)	(596)
Acquisitions of a business					(4)
Foreign currency translation adjustments			11		16
Ending balance, goodwill	6,123		6,123		6,112
National Security & Digital
Goodwill [Roll Forward]
Beginning balance, goodwill			2,758	2,755	2,755
Goodwill impairment					0
Acquisitions of a business					0
Foreign currency translation adjustments			0		3
Ending balance, goodwill	2,758		2,758		2,758
Health & Civil
Goodwill [Roll Forward]
Beginning balance, goodwill			1,366	1,366	1,366
Goodwill impairment					0
Acquisitions of a business					0
Foreign currency translation adjustments			0		0
Ending balance, goodwill	1,366		1,366		1,366
Commercial & International
Goodwill [Roll Forward]
Beginning balance, goodwill			800	1,389	1,389
Goodwill impairment					(596)
Acquisitions of a business					(4)
Foreign currency translation adjustments			11		11
Ending balance, goodwill	811		811		800
Accumulated goodwill impairment losses					596
Defense Systems
Goodwill [Roll Forward]
Beginning balance, goodwill			1,188	$ 1,186	1,186
Goodwill impairment					0
Acquisitions of a business					0
Foreign currency translation adjustments			0		2
Ending balance, goodwill	$ 1,188		$ 1,188		$ 1,188