Schedule of Segment Reporting Information by Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended												12 Months Ended
	Jan. 31, 2014		Nov. 01, 2013		Aug. 02, 2013		May 03, 2013		Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 1,295	[1]	$ 1,418	[1]	$ 1,462	[1]	$ 1,597	[1]	$ 1,580	$ 1,668	$ 1,623	$ 1,598	$ 5,772	$ 6,469	$ 5,836
Operating income (loss)	82	[1]	(5)	[1]	11	[1]	76	[1]	91	105	111	116	164	423	(58)
Amortization of intangible assets													36	37	32
Operating Segments | HES
Segment Reporting Information [Line Items]
Revenues													1,735	1,825	1,612
Operating income (loss)													21	140	139
Amortization of intangible assets													33	32	24
Operating Segments | NSS
Segment Reporting Information [Line Items]
Revenues													4,049	4,650	4,618
Operating income (loss)													292	360	400
Amortization of intangible assets													3	5	8
Operating Segments | Corporate and Other
Segment Reporting Information [Line Items]
Revenues													(9)	(1)	(390)
Operating income (loss)													(149)	(77)	(597)
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenues													$ (3)	$ (5)	$ (4)

[1] Fiscal 2014 quarterly results include increased charges related to intangible asset impairment charges (second quarter charge was $30 million and another charge in the third quarter of $19 million), bad debt expense (third quarter expense was $42 million) and separation transaction and restructuring expenses (approximately $33 million in the first and second quarters combined, $25 million in the third quarter, and $7 million in the fourth quarter). For further information see, Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations.