STOCK-BASED COMPENSATION Stock Option Activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2012 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Aggregate intrinsic value of options vested and expected to vest at March 31, 2012	$ 45,044
Aggregate intrinsic value of options exercisable at March 31, 2012	38,137
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding at March 31, 2011	5,360,000
Options granted	654,000
Options exercised	(1,831,000)
Options forfeited or expired	(879,000)
Options outstanding at March 31, 2012	3,304,000
Weighted average exercise price of options outstanding at March 31, 2011	$ 25.58
Weighted average exercise price of options granted	$ 34.93
Weighted average exercise price of options exercised	$ 20.88
Weighted average exercise price of options forfeited or expired	$ 38.96
Weighted average exercise price of options outstanding at March 31, 2012	$ 26.47
Weighted average remaining contractual life of options outstanding at March 31, 2012	3.7
Aggregate intrinsic value of options outstanding at March 31, 2012	$ 45,544
Vested and expected to vest at March 31, 2012	3,225,000
Weighted average exercise price of options vested and expected to vest at March 31, 2012	$ 26.29
Weighted average remaining contractual life of options vested and expected to vest at March 31, 2012	3.6
Exercisable at March 31, 2012	2,316,000
Weighted average exercise price of options exercisable at March 31, 2012	$ 23.79
Weighted average remaining contractual life of options exercisable at March 31, 2012	2.8