Schedule of Depreciation using Estimated Useful Lives (Detail)	12 Months Ended
	Jan. 30, 2015
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	2 years
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	10 years
Building | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	30 years
Building | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	40 years
Building improvements and leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	Shorter of lease term or 25
Building improvements and leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	25 years
Office furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	6 years
Office furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	9 years
Generation facility
Property, Plant and Equipment [Line Items]
Estimated useful lives (in years)	25 years