Comprehensive Income (Components Of Comprehensive Income, Net Of Tax) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Comprehensive Income [Abstract]
Net income	$ 102,177	$ 198,290	$ 364,032	$ 460,884
Foreign currency translation adjustments	(5,897)	(543)	(41,654)	13,966
Unrealized gain (loss) on derivative instruments, and other	14,962	(7,367)	(29,182)	19,141
Comprehensive income	$ 111,242	$ 190,380	$ 293,196	$ 493,991