STOCK-BASED COMPENSATION Stock Option Activity (Details) (Stock Options, USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Mar. 31, 2015
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, March 31, 2014 (shares)	1,934,000
Options granted (shares)	298,000
Options exercised (shares)	(633,000)
Options forfeited or expired (shares)	(41,000)
Options outstanding, March 31, 2015 (shares)	1,558,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price of options outstanding at March 31, 2014 (in dollars per share)	$ 31.91
Weighted average exercise price of options granted (in dollars per share)	$ 47.11
Weighted average exercise price of options exercised (in dollars per share)	$ 27.02
Weighted average exercise price of options forfeited or expired (in dollars per share)	$ 39.74
Weighted average exercise price of options outstanding at March 31, 2015 (in dollars per share)	$ 36.59
Weighted average remaining contractual life of options outstanding at March 31, 2015 (in years)	4 years 37 days
Aggregate intrinsic value of options outstanding at March 31, 2015	$ 27,046
Vested or expected to vest at March 31, 2015 (in shares)	1,529,000
Weighted average exercise price of options vested or expected to vest at March 31, 2015 (in dollars per share)	$ 36.40
Weighted average remaining contractual life of options vested or expected to vest at March 31, 2015 (in years)	4 years 0 days
Aggregate intrinsic value of options vested or expected to vest at March 31, 2015	26,841
Exercisable at March 31, 2015 (in shares)	1,083,000
Weighted average exercise price of options exercisable at March 31, 2015 (in dollars per share)	$ 32.93
Weighted average remaining contractual life of options exercisable at March 31, 2015 (in years)	3 years 110 days
Aggregate intrinsic value of options exercisable at March 31, 2015	$ 22,774