Business Segments (Segment Reporting Information by Segment) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Total revenues	$ 3,975	$ 3,699
Total operating income	415	265
Corporate
Segment Reporting Information [Line Items]
Total operating income	(37)	(29)
National Security and Digital | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	1,793	1,757
Total operating income	175	145
Health & Civil | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	1,199	1,008
Total operating income	222	113
Commercial & International | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	509	489
Total operating income	34	13
Defense Systems | Operating Segments
Segment Reporting Information [Line Items]
Total revenues	474	445
Total operating income	$ 21	$ 23