Fair Value Measurements (Schedule Of Items Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2012	Feb. 29, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	$ 80,965	$ 458,090
Mutual fund investments	3,495	2,586
Derivative instruments	8	317
Total assets at fair value	84,468	460,993
Percent of total assets at fair value	100.00%	100.00%
Percent of total assets	1.00%	5.50%
Derivative instruments	4,608	1,978
Liabilities Fair Value Disclosure	4,608	1,978
Percent of total liabilities	0.10%	0.00%
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market securities	80,965	458,090
Mutual fund investments	3,495	2,586
Derivative instruments	0	0
Total assets at fair value	84,460	460,676
Percent of total assets at fair value	100.00%	99.90%
Percent of total assets	1.00%	5.50%
Derivative instruments	0	0
Liabilities Fair Value Disclosure	0	0
Percent of total liabilities	0.00%	0.00%
Level 2 [Member]
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	8	317
Total assets at fair value	8	317
Percent of total assets at fair value	0.00%	0.10%
Percent of total assets	0.00%	0.00%
Derivative instruments	4,608	1,978
Liabilities Fair Value Disclosure	$ 4,608	$ 1,978
Percent of total liabilities	0.10%	0.00%