STOCK-BASED COMPENSATION Stock Option Activity (Details) (Stock Options [Member], USD $) Share data in Thousands, except Per Share data, unless otherwise specified	6 Months Ended
	Sep. 30, 2011 years	Sep. 30, 2010
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding at March 31, 2011	5,360
Weighted average exercise price of options outstanding, March 31, 2011	$ 25.58
Options granted	424
Weighted average exercise price of options granted	$ 35.54
Options exercised	(795)
Weighted average exercise price of options exercised	$ 20.95
Options forfeited or expired	(703)
Weighted average exercise price of options forfeited or expired	$ 39.33
Options outstanding at September 30, 2011	4,286
Weighted average exercise price of options outstanding, September 30, 2011	$ 25.17
Weighted average remaining contractual life of options outstanding at September 30, 2011	3.6
Aggregate intrinsic value of options outstanding at September 30, 2011	$ 21,669,000
Vested and expected to vest at September 30, 2011	4,186
Weighted average exercise price of options vested and expected to vest at September 30, 2011	$ 24.99
Weighted average remaining contractual life of options vested and expected to vest at September 30, 2011	3.5
Aggregate intrinsic value of options vested and expected to vest at September 30, 2011	21,573,000
Exercisable at September 30, 2011	3,119
Weighted average exercise price of options exercisable at September 30, 2011	$ 23.18
Weighted average remaining contractual life of options exercisable at September 30, 2011	2.7
Aggregate intrinsic value of options exercisable at September 30, 2011	19,052,000
Total intrinsic value of options exercised	11,700,000	5,100,000
Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options	16,700,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 10,000,000
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition	1.9