Estimated Useful Life of Various Categories of Property and Equipment (Detail)
9 Months Ended
Sep. 29, 2012
Leasehold Improvements
 
Property, Plant and Equipment [Line Items]  
Leasehold improvements Lesser of term of lease or 10 years
Furniture and Fixtures
 
Property, Plant and Equipment [Line Items]  
Estimated useful life 7 years
Computer hardware and software
 
Property, Plant and Equipment [Line Items]  
Estimated useful life 3 years
Equipment
 
Property, Plant and Equipment [Line Items]  
Estimated useful life 5 years