BUSINESS SEGMENT INFORMATION - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2026	Oct. 03, 2025	Oct. 02, 2026	Oct. 03, 2025
Disaggregation of Revenue [Line Items]
Revenue	$ 6,060	$ 5,659	$ 17,685	$ 16,217
Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(80)	(88)	(253)	(292)
Total segment
Disaggregation of Revenue [Line Items]
Revenue	6,065	5,658	17,690	16,070
SMS \| United States
Disaggregation of Revenue [Line Items]
Revenue	2,554	2,415	7,599	6,823
SMS \| International
Disaggregation of Revenue [Line Items]
Revenue	512	364	1,378	1,083
SMS \| Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	2,030	1,898	6,078	5,513
SMS \| Cost-type
Disaggregation of Revenue [Line Items]
Revenue	1,036	881	2,899	2,393
SMS \| Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(27)	(24)	(72)	(78)
SMS \| Total segment
Disaggregation of Revenue [Line Items]
Revenue	3,093	2,803	9,049	7,984
CSD \| United States
Disaggregation of Revenue [Line Items]
Revenue	1,125	1,154	3,238	3,358
CSD \| International
Disaggregation of Revenue [Line Items]
Revenue	830	730	2,410	2,073
CSD \| Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,648	1,585	4,753	4,596
CSD \| Cost-type
Disaggregation of Revenue [Line Items]
Revenue	307	299	895	835
CSD \| Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(40)	(51)	(145)	(174)
CSD \| Total segment
Disaggregation of Revenue [Line Items]
Revenue	1,995	1,935	5,793	5,605
MSL \| United States
Disaggregation of Revenue [Line Items]
Revenue	932	859	2,728	2,463
MSL \| International
Disaggregation of Revenue [Line Items]
Revenue	112	137	337	272
MSL \| Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	711	634	2,058	1,715
MSL \| Cost-type
Disaggregation of Revenue [Line Items]
Revenue	333	362	1,007	1,020
MSL \| Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(13)	(12)	(36)	(38)
MSL \| Total segment
Disaggregation of Revenue [Line Items]
Revenue	1,057	1,008	3,101	2,773
Other \| United States
Disaggregation of Revenue [Line Items]
Revenue				61
Other \| International
Disaggregation of Revenue [Line Items]
Revenue				84
Other \| Fixed-price
Disaggregation of Revenue [Line Items]
Revenue				145
Other \| Cost-type
Disaggregation of Revenue [Line Items]
Revenue				0
Other \| Intersegment
Disaggregation of Revenue [Line Items]
Revenue				(1)
Other \| Total segment
Disaggregation of Revenue [Line Items]
Revenue				146
Prime contractor \| SMS
Disaggregation of Revenue [Line Items]
Revenue	2,324	2,027	6,787	5,773
Prime contractor \| CSD
Disaggregation of Revenue [Line Items]
Revenue	1,293	1,335	3,785	3,712
Prime contractor \| MSL
Disaggregation of Revenue [Line Items]
Revenue	277	274	772	741
Prime contractor \| Other
Disaggregation of Revenue [Line Items]
Revenue				72
Subcontractor \| SMS
Disaggregation of Revenue [Line Items]
Revenue	742	752	2,190	2,133
Subcontractor \| CSD
Disaggregation of Revenue [Line Items]
Revenue	662	549	1,863	1,719
Subcontractor \| MSL
Disaggregation of Revenue [Line Items]
Revenue	$ 767	$ 722	$ 2,293	1,994
Subcontractor \| Other
Disaggregation of Revenue [Line Items]
Revenue				$ 73