Commitments and contingencies (Details) (USD $)	1 Months Ended		12 Months Ended
	Aug. 31, 2007	Jan. 29, 1999 Y	Feb. 03, 2012 Y	Jan. 28, 2011	Jan. 29, 2010
Commitments and contingencies
Typical period of primary lease term for operating lease, build-to-suit, minimum (in years)			10
Typical period of primary lease term for operating lease, build-to-suit, maximum (in years)			15
Percentage of leased stores with provision for contingent rentals			26.00%
Period for which asset was taken on lease under sale and leaseback transaction (in years)		23
Face value of promissory note purchased	$ 34,300,000
Future minimum payments for operating leases
2012			537,842,000
2013			495,373,000
2014			442,913,000
2015			379,693,000
2016			324,512,000
Thereafter			1,479,668,000
Total minimum payments			3,660,001,000
Total minimum payments for capital leases			7,400,000
Present value of net minimum capital lease payments			5,100,000
Effective interest rate at which capital leases are discounted (as a percent)			6.80%
Gross property and equipment recorded under capital lease			29,000,000	31,000,000
Accumulated depreciation on property and equipment recorded under capital lease			7,300,000	7,400,000
Operating lease rent expenses
Minimum rentals			525,486,000	471,402,000	407,379,000
Contingent rentals			16,856,000	17,882,000	21,248,000
Operating lease rent expenses			542,342,000	489,284,000	428,627,000
Amortization of leasehold interests			$ 21,000,000	$ 25,700,000	$ 37,200,000