Fair Value Measurements (Schedule Of Items Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Nov. 30, 2019	Feb. 28, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 234,676	$ 372,448
Mutual fund investments	21,905	19,263
Derivative instruments	3,711	1,844
Total assets at fair value	$ 260,292	$ 393,555
Percent of total assets at fair value	100.00%	100.00%
Percent of total assets	1.30%	2.10%
Liabilities: Derivative instruments	$ (1,653)	$ (6,120)
Total liabilities at fair value	$ (1,653)	$ (6,120)
Percent of total liabilities	0.00%	0.00%
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 234,676	$ 372,448
Mutual fund investments	21,905	19,263
Derivative instruments	0	0
Total assets at fair value	$ 256,581	$ 391,711
Percent of total assets at fair value	98.60%	99.50%
Percent of total assets	1.30%	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	3,711	1,844
Total assets at fair value	$ 3,711	$ 1,844
Percent of total assets at fair value	1.40%	0.50%
Percent of total assets	0.00%	0.00%
Liabilities: Derivative instruments	$ (1,653)	$ (6,120)
Total liabilities at fair value	$ (1,653)	$ (6,120)
Percent of total liabilities	0.00%	0.00%