Business Segments (Schedule of segment reporting information by segment) (Detail) - USD ($) $ in Millions	3 Months Ended
	Apr. 03, 2020	Mar. 29, 2019
Segment Reporting Information [Line Items]
Revenues	$ 2,889	$ 2,577
Operating income (loss)	192	192
Operating Segments | Defense Solutions
Segment Reporting Information [Line Items]
Revenues	1,705	1,491
Operating income (loss)	95	104
Operating Segments | Civil
Segment Reporting Information [Line Items]
Revenues	654	623
Operating income (loss)	59	58
Operating Segments | Health
Segment Reporting Information [Line Items]
Revenues	530	463
Operating income (loss)	73	45
Corporate
Segment Reporting Information [Line Items]
Operating income (loss)	$ (35)	$ (15)