Business Segments (Schedule of Segment Reporting Information by Segment) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 01, 2016	Jul. 03, 2015	Jul. 01, 2016	Jul. 03, 2015
Segment Reporting Information [Line Items]
Revenues	$ 1,288	$ 1,257	$ 2,600	$ 2,503
Operating income (loss)	$ 75	$ 64	$ 164	$ 102
Operating income margin (in percentage)	5.80%	5.10%	6.30%	4.10%
Segments | National Security Solutions
Segment Reporting Information [Line Items]
Revenues	$ 915	$ 879	$ 1,813	$ 1,741
Operating income (loss)	$ 61	$ 74	$ 133	$ 136
Operating income margin (in percentage)	6.70%	8.40%	7.30%	7.80%
Segments | Health and Infrastructure Sector
Segment Reporting Information [Line Items]
Revenues	$ 373	$ 379	$ 787	$ 764
Operating income (loss)	$ 39	$ (7)	$ 75	$ (14)
Operating income margin (in percentage)	10.50%	(1.80%)	9.50%	(1.80%)
Segments | Corporate and Other
Segment Reporting Information [Line Items]
Revenues	$ 0	$ (1)	$ 0	$ (2)
Operating income (loss)	$ (25)	$ (3)	$ (44)	$ (20)