Business Segment Information (Detail 2) (Sales Revenue, Net)	12 Months Ended
	Jan. 30, 2015	Jan. 31, 2014	Jan. 31, 2013
Government Contracts Concentration Risk
Segment Reporting Information [Line Items]
Percentage of sales	97.00%	97.00%	96.00%
Government Contracts Concentration Risk | U S Army
Segment Reporting Information [Line Items]
Percentage of sales	28.00%	29.00%	26.00%
Government Contracts Concentration Risk | U S Navy
Segment Reporting Information [Line Items]
Percentage of sales	20.00%	21.00%	21.00%
Government Contracts Concentration Risk | Other DoD
Segment Reporting Information [Line Items]
Percentage of sales	22.00%	22.00%	26.00%
Government Contracts Concentration Risk | Other Federal Government
Segment Reporting Information [Line Items]
Percentage of sales	27.00%	25.00%	23.00%
Customer Concentration Risk
Segment Reporting Information [Line Items]
Percentage of sales	100.00%	100.00%	100.00%
Customer Concentration Risk | Other
Segment Reporting Information [Line Items]
Percentage of sales	3.00%	3.00%	4.00%