Derivative financial instruments (Details) (USD $)	12 Months Ended				12 Months Ended
	Jan. 31, 2014	Feb. 01, 2013	Feb. 03, 2012	Jan. 31, 2014 Interest rate swaps Cash flow hedge	Jan. 31, 2014 Treasury locks Cash flow hedge	Apr. 11, 2013 Treasury locks Cash flow hedge
Cash flow hedges of interest rate risk
Combined notional value				$ 875,000,000		$ 700,000,000
Loss related to effective portion of derivative recognized in OCI	16,036,000	9,626,000	3,836,000		13,200,000
(Gain) loss related to ineffective portion of derivative recognized in Other (income) expense		(2,392,000)	312,000		0
Estimated amount to be reclassified during the next 52 week period	$ 4,700,000