Annual report pursuant to Section 13 and 15(d)

Summary of significant accounting policies - Estimated Useful Lives or Expected Lease Term (Detail)

v2.4.0.6
Summary of significant accounting policies - Estimated Useful Lives or Expected Lease Term (Detail)
 12 Months Ended
Feb. 02, 2013
Minimum [Member] | Equipment and fixtures [Member]
  
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]  
Estimated useful lives or the expected lease term 3 years
Minimum [Member] | Electronic equipment and software [Member]
  
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]  
Estimated useful lives or the expected lease term 3 years
Maximum [Member] | Equipment and fixtures [Member]
  
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]  
Estimated useful lives or the expected lease term 10 years
Maximum [Member] | Electronic equipment and software [Member]
  
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]  
Estimated useful lives or the expected lease term 5 years
Average [Member] | Leasehold improvements [Member]
  
Interest Cost Capitalized And Depreciation And Amortization Expenses For Property, Plant and Equipment [Line Items]  
Estimated useful lives or the expected lease term 10 years