Assets and liabilities measured at fair value (Details) (USD $) In Thousands, unless otherwise specified	Oct. 28, 2011
Reported amount | Prepaid expenses and other current assets
Assets:
Trading securities	$ 1,756
Reported amount | Other assets, net
Assets:
Trading securities	4,985
Reported amount | Current portion of long-term debt obligations
Liabilities:
Long-term obligations	763
Reported amount | Long-term obligations
Liabilities:
Long-term obligations	2,721,061
Reported amount | Accrued expenses and other current liabilities
Liabilities:
Derivative financial instruments	7,842
Deferred compensation	1,761
Reported amount | Non-current Other Liabilities
Liabilities:
Derivative financial instruments	7,273
Deferred compensation	16,380
Fair value measurements on recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Trading securities	6,741
Liabilities:
Long-term obligations	2,760,831
Deferred compensation	18,141
Fair value measurements on recurring basis | Significant Other Observable Inputs (Level 2)
Liabilities:
Long-term obligations	19,827
Derivative financial instruments	15,115
Fair value measurements on recurring basis | Balance at the end of the period
Assets:
Trading securities	6,741
Liabilities:
Long-term obligations	2,780,658
Derivative financial instruments	15,115
Deferred compensation	$ 18,141