Fair Value Measurements (Schedule Of Items Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	May 31, 2019	Feb. 28, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 415,713	$ 372,448
Mutual fund investments	21,329	19,263
Derivative instruments	593	1,844
Total assets at fair value	$ 437,635	$ 393,555
Percent of total assets at fair value	100.00%	100.00%
Percent of total assets	2.20%	2.10%
Liabilities: Derivative instruments	$ (13,213)	$ (6,120)
Total liabilities at fair value	$ (13,213)	$ (6,120)
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	$ 415,713	$ 372,448
Mutual fund investments	21,329	19,263
Derivative instruments	0	0
Total assets at fair value	$ 437,042	$ 391,711
Percent of total assets at fair value	99.90%	99.50%
Percent of total assets	2.20%	2.10%
Liabilities: 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	593	1,844
Total assets at fair value	$ 593	$ 1,844
Percent of total assets at fair value	0.10%	0.50%
Percent of total assets	0.00%	0.00%
Liabilities: Derivative instruments	$ (13,213)	$ (6,120)
Total liabilities at fair value	$ (13,213)	$ (6,120)
Percent of total liabilities	0.10%	0.00%