Employee Benefit Plans (Schedule Of Stock Options Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Jan. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding at January 31, 2012	1,651,400
Shares granted	6,236
Shares, Exercised	(1,110,020)
Shares, Canceled	(45,391)
Shares, Outstanding at January 31, 2013	502,225
Vested and expected to vest at January 31, 2013, Shares	499,712
Exercisable at January 31, 2013, Shares	354,391
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted-average exercise price, Outstanding at January 31, 2012	$ 33.89
Weighted-average exercise price, Granted	$ 54.03
Weighted-average exercise price, Exercised	$ 34.12
Weighted-average exercise price, Canceled	$ 37.03
Weighted-average exercise price, Outstanding at January 31, 2013	$ 33.33
Weighted-average exercise price,, vested and expected to vest at January 31, 2013	$ 33.33
Weighted-average exercise price, Exercisable at January 31, 2013	$ 37.74
Weighted-Average remaining contractual term (in years), Outstanding at January 31, 2012	3 years
Weighted-Average remaining contractual term (in years), Vested and expected to vest at January 31, 2012	3 years
Weighted-Average remaining contractual term (in years), Exercisable at January 31, 2012	1 year 8 months 12 days
Aggregate intrinsic value, Outstanding	$ 8,848
Aggregate intrinsic value, Vested and expected to vest at January 31, 2013	8,802
Aggregate intrinsic value, Exercisable at January 31, 2013	$ 4,669