Business Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Oct. 01, 2021	Sep. 30, 2022	Oct. 01, 2021
Segment Reporting Information [Line Items]
Revenues	$ 3,608	$ 3,483	$ 10,699	$ 10,246
Total operating income	281	305	823	882
Corporate
Segment Reporting Information [Line Items]
Total operating income	(26)	(23)	(81)	(73)
Defense Solutions
Segment Reporting Information [Line Items]
Revenues	2,075	2,009	6,176	5,971
Defense Solutions | Operating Segments
Segment Reporting Information [Line Items]
Total operating income	137	140	409	429
Civil
Segment Reporting Information [Line Items]
Revenues	874	792	2,526	2,357
Civil | Operating Segments
Segment Reporting Information [Line Items]
Total operating income	79	58	160	187
Health
Segment Reporting Information [Line Items]
Revenues	659	682	1,997	1,918
Health | Operating Segments
Segment Reporting Information [Line Items]
Total operating income	$ 91	$ 130	$ 335	$ 339