Share Based Compensation (Stock Option Activity) (Details) (USD $)	3 Months Ended
	Apr. 28, 2012 yr
Stock option activity
Number of Shares Outstanding at start date	714,997
Number of Shares Outstanding, Weighted average Exercise Price	$ 60.72
Exercised, Number of Shares	(3,750)
Exercised, Weighted average Exercise Price	$ 26.60
Forfeited or cancelled, Number of Shares	0
Forfeited or cancelled, Weighted-Average Exercise Price	$ 0
Number of Shares Outstanding at end date	711,247
Number of Shares Outstanding, Weighted average Exercise Price	$ 60.90
Number of Shares Outstanding, Aggregate Intrinsic Value	$ 4,552,433
Number of Shares Outstanding, Weighted- Average Remaining Contractual Life	4.3
Stock options exercisable	695,247
Stock options exercisable, Weighted-Average Exercise Price	$ 61.83
Stock options exercisable, Aggregate Intrinsic Value	4,067,823
Stock options exercisable, Weighted-Average Remaining Contractual Life	4.2
Stock options expected to become exercisable in the future as of end date	15,454
Stock options expected to become exercisable in the future as of end date, Aggregate Intrinsic Value	$ 468,174
Stock options expected to become exercisable in the future as of end date, Weighted Average Exercise Price	$ 20.58
Stock options expected to become exercisable in the future as of end date, Weighted Average Remaining Contractual Life	6.6