Debt (7.5% Convertible Notes) (Details) (Convertible Notes 7.50%, Maturing Fiscal Year 2013 [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	6 Months Ended		12 Months Ended
	Jul. 28, 2012	Jul. 30, 2011	Jan. 28, 2012
Convertible Notes 7.50%, Maturing Fiscal Year 2013 [Member]
Debt Instrument [Line Items]
Principal amount	$ 120,000	$ 120,000	$ 120,000
Debt interest rate	7.50%	7.50%	7.50%
Debt maturity date	2013	2013	2013
Debt issuance date	May 2009
Debt conversion rate per share	$ 5.54
Common stock to be issued upon conversion, shares	21,670
Non-convertible borrowing rate	13.00%
Fair value of liability component, upon issuance	97,994
Carrying amount of the equity component	$ 22,006
Debt discount amortization period	4.5 years