Fair Value Measurements (Schedule Of Items Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Feb. 29, 2016	Feb. 28, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 439,943	$ 380,100
Mutual fund investments	13,622	9,242
Derivative instruments	587	1,201
Total assets at fair value	$ 454,152	$ 390,543
Percent of total assets at fair value	100.00%	100.00%
Percent of total assets	3.10%	3.00%
Derivative instruments	$ (8,024)	$ (1,064)
Total liabilities at fair value	$ (8,024)	$ (1,064)
Percent of total liabilities	0.10%	0.00%
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 439,943	$ 380,100
Mutual fund investments	13,622	9,242
Derivative instruments	0	0
Total assets at fair value	$ 453,565	$ 389,342
Percent of total assets at fair value	99.90%	99.70%
Percent of total assets	3.10%	2.90%
Derivative instruments	$ 0	$ 0
Total liabilities at fair value	$ 0	$ 0
Percent of total liabilities	0.00%	0.00%
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 0	$ 0
Mutual fund investments	0	0
Derivative instruments	587	1,201
Total assets at fair value	$ 587	$ 1,201
Percent of total assets at fair value	0.10%	0.30%
Percent of total assets	0.00%	0.00%
Derivative instruments	$ (8,024)	$ (1,064)
Total liabilities at fair value	$ (8,024)	$ (1,064)
Percent of total liabilities	0.10%	0.00%