Share-Based Compensation (Stock Option Activity) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Aug. 31, 2012	Aug. 31, 2011
Share-Based Compensation [Abstract]
Outstanding as of February 29, 2012, Number of Shares	12,578,000
Options granted, Number of Shares	2,233,624	1,933,690
Options exercised, Number of Shares	(792,000)
Options forfeited or expired, Number of Shares	(33,000)
Outstanding as of August 31, 2012, Number of Shares	13,987,000
Exercisable as of August 31, 2012, Number of Shares	9,221,000
Outstanding as of February 29, 2012, Weighted Average Exercise Price	$ 19.84
Options granted, Weighted Average Exercise Price	$ 31.60
Options exercised, Weighted Average Exercise Price	$ 15.86
Options forfeited or expired, Weighted Average Exercise Price	$ 24.70
Outstanding as of August 31, 2012, Weighted Average Exercise Price	$ 21.93
Exercisable as of August 31, 2012, Weighted Average Exercise Price	$ 18.61
Outstanding as of August 31, 2012, Weighted Average Remaining Contractual Life (Years)	3 years 9 months 18 days
Exercisable as of August 31, 2012, Weighted Average Remaining Contractual Life (Years)	2 years 10 months 24 days
Outstanding as of August 31, 2012, Aggregate Intrinsic Value	$ 127,631
Exercisable as of August 31, 2012, Aggregate Intrinsic Value	$ 112,031