Assets and liabilities measured at fair value (Details) (USD $) In Thousands, unless otherwise specified	Aug. 03, 2012
Reported amount | Prepaid expenses and other current assets
Assets:
Trading securities	$ 2,676
Reported amount | Other assets, net
Assets:
Trading securities	3,632
Reported amount | Current portion of long-term debt obligations
Liabilities:
Long-term obligations	344
Reported amount | Long-term obligations
Liabilities:
Long-term obligations	2,887,251
Reported amount | Accrued expenses and other current liabilities
Liabilities:
Derivative financial instruments	3,117
Deferred compensation	3,667
Reported amount | Non-current Other liabilities
Liabilities:
Derivative financial instruments	5,376
Deferred compensation	16,733
Fair value measurements on recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Trading securities	6,308
Liabilities:
Long-term obligations	2,893,651
Deferred compensation	20,400
Fair value measurements on recurring basis | Significant Other Observable Inputs (Level 2)
Liabilities:
Long-term obligations	19,195
Derivative financial instruments	8,493
Fair value measurements on recurring basis | Balance at the end of the period
Assets:
Trading securities	6,308
Liabilities:
Long-term obligations	2,912,846
Derivative financial instruments	8,493
Deferred compensation	$ 20,400