Schedule of Segment Reporting Information by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended												12 Months Ended
	Jan. 30, 2015		Oct. 31, 2014		Aug. 01, 2014		May 02, 2014		Jan. 31, 2014	Nov. 01, 2013	Aug. 02, 2013	May 03, 2013	Jan. 30, 2015	Jan. 31, 2014	Jan. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 1,169	[1]	$ 1,276	[1]	$ 1,306	[1]	$ 1,312	[1]	$ 1,291	$ 1,414	$ 1,457	$ 1,593	$ 5,063	$ 5,755	$ 6,449
Operating income (loss)	37	[1]	72	[1]	(410)	[1]	87	[1]	81	(5)	10	77	(214)	163	421
Amortization of intangible assets													15	35	35
Operating Segments | NSS
Segment Reporting Information [Line Items]
Revenues													3,594	4,049	4,650
Operating income (loss)													286	292	360
Amortization of intangible assets													0	3	5
Operating Segments | HES
Segment Reporting Information [Line Items]
Revenues													1,485	1,718	1,805
Operating income (loss)													(472)	20	138
Amortization of intangible assets													15	32	30
Operating Segments | Corporate and Other
Segment Reporting Information [Line Items]
Revenues													(16)	(9)	(1)
Operating income (loss)													(28)	(149)	(77)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues													$ 0	$ (3)	$ (5)

[1] Fiscal 2014 quarterly results include the following charges: 1) intangible asset impairment charges of $30 million and $19 million in the second and third quarter, respectively; 2) bad debt expense for certain receivables related to two energy design-build construction projects of $42 million in the third quarter; and 3) separation transaction and restructuring expenses in each of the quarters of approximately $14 million, $19 million, $25 million, and $7 million, respectively. For further information see,