Net Earnings Per Share (Basic And Dilutive Net Earnings Per Share Reconciliations) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Feb. 28, 2014	Nov. 30, 2013	Aug. 31, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 28, 2014	Feb. 28, 2013	Feb. 29, 2012
Schedule of Basic and Dilutive Net Earnings Per Share Reconciliation [Line Items]
Net earnings	$ 99,209	$ 106,452	$ 140,274	$ 146,651	$ 107,221	$ 94,681	$ 111,636	$ 120,746	$ 492,586	$ 434,284	$ 413,795
Less net earnings allocable to restricted stock									0	0	166
Net earnings available for basic and diluted common shares									$ 492,586	$ 434,284	$ 413,629
Weighted average common shares outstanding									223,589	228,095	226,282
Weighted average common shares and dilutive potential common shares									227,584	231,823	230,721
Basic net earnings per share	$ 0.45	$ 0.48	$ 0.63	$ 0.65	$ 0.47	$ 0.41	$ 0.49	$ 0.53	$ 2.20	$ 1.90	$ 1.83
Diluted net earnings per share	$ 0.44	$ 0.47	$ 0.62	$ 0.64	$ 0.46	$ 0.41	$ 0.48	$ 0.52	$ 2.16	$ 1.87	$ 1.79
Stock Options [Member]
Schedule of Basic and Dilutive Net Earnings Per Share Reconciliation [Line Items]
Dilutive potential common shares									3,255	3,161	3,608
Stock-Settled Restricted Stock Units [Member]
Schedule of Basic and Dilutive Net Earnings Per Share Reconciliation [Line Items]
Dilutive potential common shares									740	567	831