Assets and liabilities measured at fair value (Details) (USD $) In Thousands, unless otherwise specified	May 04, 2012
Reported amount | Prepaid expenses and other current assets
Assets:
Trading securities	$ 1,637
Reported amount | Other assets, net
Assets:
Trading securities	5,038
Reported amount | Current portion of long-term debt obligations
Liabilities:
Long-term obligations	459
Reported amount | Long-term obligations
Liabilities:
Long-term obligations	2,880,920
Reported amount | Accrued expenses and other current liabilities
Liabilities:
Derivative financial instruments	6,764
Deferred compensation	1,679
Reported amount | Non-current Other Liabilities
Liabilities:
Deferred compensation	19,240
Fair value measurements on recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Trading securities	6,675
Liabilities:
Long-term obligations	2,904,606
Deferred compensation	20,919
Fair value measurements on recurring basis | Significant Other Observable Inputs (Level 2)
Liabilities:
Long-term obligations	19,382
Derivative financial instruments	6,764
Fair value measurements on recurring basis | Balance at the end of the period
Assets:
Trading securities	6,675
Liabilities:
Long-term obligations	2,923,988
Derivative financial instruments	6,764
Deferred compensation	$ 20,919