Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Millions	3 Months Ended
	Apr. 01, 2016	Apr. 03, 2015
Segment Reporting Information [Line Items]
Revenues	$ 1,312	$ 1,246
Operating income (loss)	$ 89	$ 38
Operating income margin (in percentage)	6.80%	3.00%
Segments | National Security Solutions
Segment Reporting Information [Line Items]
Revenues	$ 898	$ 862
Operating income (loss)	$ 72	$ 62
Operating income margin (in percentage)	8.00%	7.20%
Segments | Health and Infrastructure Sector
Segment Reporting Information [Line Items]
Revenues	$ 414	$ 385
Operating income (loss)	$ 36	$ (7)
Operating income margin (in percentage)	8.70%	(1.80%)
Segments | Corporate and Other
Segment Reporting Information [Line Items]
Revenues	$ 0	$ (1)
Operating income (loss)	$ (19)	$ (17)