Current and long-term obligations (Details) (USD $)	9 Months Ended		1 Months Ended
	Oct. 28, 2011	Oct. 29, 2010	Jul. 29, 2011 10.625% senior notes due 2015	Apr. 29, 2011 10.625% senior notes due 2015	Oct. 01, 2010 10.625% senior notes due 2015	May 28, 2010 10.625% senior notes due 2015	Jul. 15, 2011 10.625% senior notes due 2015	Sep. 29, 2010 10.625% senior notes due 2015	May 06, 2010 10.625% senior notes due 2015
Current and long-term obligations
Principal amount of notes repurchased			$ 839,300,000	$ 25,000,000	$ 65,000,000	$ 50,000,000
Notes stated interest rate percentage (as a percent)							10.625%
Redemption price (as a percent)				107.00%			105.313%	110.75%	111.00%
Loss on debt retirement, net	60,303,000	14,576,000	58,100,000	2,200,000	8,200,000	6,500,000
Balance of senior secured assets-based revolving credit facility	$ 287,800,000