Schedule of Segment Reporting Information by Segment (Detail) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 30, 2015	Oct. 02, 2015	Oct. 31, 2014	Oct. 02, 2015	Oct. 31, 2014
Segment Reporting Information [Line Items]
Revenues	$ 373	$ 1,302	$ 1,276	$ 3,805	$ 3,894
Operating income (loss)	$ (23)	94	72	196	(251)
Segments | National Security Solutions
Segment Reporting Information [Line Items]
Revenues		878	906	2,619	2,775
Operating income (loss)		78	72	214	227
Segments | Health and Engineering
Segment Reporting Information [Line Items]
Revenues		418	373	1,182	1,126
Operating income (loss)		13	4	(1)	(455)
Segments | Corporate and Other
Segment Reporting Information [Line Items]
Revenues		6	(3)	4	(7)
Operating income (loss)		$ 3	$ (4)	$ (17)	$ (23)