Share-Based Compensation (Composition Of Share-Based Compensation Expense-By Grant Type) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2012	Aug. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	$ 14,892	$ 11,558	$ 30,709	$ 26,792
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	5,528	4,899	14,241	12,885
Cash-Settled Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	5,692	3,520	8,392	6,867
Stock-Settled Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	2,844	2,292	7,023	5,838
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	278	265	503	489
Stock Grants To Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	550	550	550	550
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense, before income taxes	$ 0	$ 32	$ 0	$ 163