BUSINESS SEGMENT INFORMATION - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 03, 2026	Mar. 28, 2025
Disaggregation of Revenue [Line Items]
Revenue	$ 5,744	$ 5,132
Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(91)	(74)
Operating segments
Disaggregation of Revenue [Line Items]
Revenue	5,744	4,986
SMS | United States
Disaggregation of Revenue [Line Items]
Revenue	2,540	2,028
SMS | International
Disaggregation of Revenue [Line Items]
Revenue	427	357
SMS | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,910	1,658
SMS | Cost-type
Disaggregation of Revenue [Line Items]
Revenue	1,057	727
SMS | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(23)	(26)
SMS | Operating segments
Disaggregation of Revenue [Line Items]
Revenue	2,990	2,411
CSD | United States
Disaggregation of Revenue [Line Items]
Revenue	1,037	1,091
CSD | International
Disaggregation of Revenue [Line Items]
Revenue	761	689
CSD | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	1,520	1,493
CSD | Cost-type
Disaggregation of Revenue [Line Items]
Revenue	278	287
CSD | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(57)	(29)
CSD | Operating segments
Disaggregation of Revenue [Line Items]
Revenue	1,855	1,809
MSL | United States
Disaggregation of Revenue [Line Items]
Revenue	874	795
MSL | International
Disaggregation of Revenue [Line Items]
Revenue	105	27
MSL | Fixed-price
Disaggregation of Revenue [Line Items]
Revenue	643	505
MSL | Cost-type
Disaggregation of Revenue [Line Items]
Revenue	336	317
MSL | Intersegment
Disaggregation of Revenue [Line Items]
Revenue	(11)	(18)
MSL | Operating segments
Disaggregation of Revenue [Line Items]
Revenue	990	840
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 | Operating segments
Disaggregation of Revenue [Line Items]
Revenue		146
Prime contractor | SMS
Disaggregation of Revenue [Line Items]
Revenue	2,286	1,725
Prime contractor | CSD
Disaggregation of Revenue [Line Items]
Revenue	1,192	1,173
Prime contractor | MSL
Disaggregation of Revenue [Line Items]
Revenue	250	222
Prime contractor | Other
Disaggregation of Revenue [Line Items]
Revenue		72
Subcontractor | SMS
Disaggregation of Revenue [Line Items]
Revenue	681	660
Subcontractor | CSD
Disaggregation of Revenue [Line Items]
Revenue	606	607
Subcontractor | MSL
Disaggregation of Revenue [Line Items]
Revenue	$ 729	600
Subcontractor | Other
Disaggregation of Revenue [Line Items]
Revenue		$ 73