DEBT (Details)			1 Months Ended	12 Months Ended
	Apr. 28, 2017	May 08, 2011	May 31, 2015 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($)
Debt Disclosure [Line Items]
Proceeds from issuance of senior notes, net of issuance costs				$ 0	$ 488,401,000	$ 0
Credit facility expiration date				May 09, 2020
Commitment fee percentage				0.37%
Outstanding borrowings under line of credit				$ 0
EBITDA		3
Minimum required liquid funds				300,000,000.0
Restructuring and other related charges (credits)				$ (109,000)	16,160,000	$ 0
Line Of Credit Facility Interest Rate Spread Below The Banks Announced Prime Rate
Debt Disclosure [Line Items]
Basis spread of variable rate				1.20%
Line Of Credit Facility Interest Rate Spread Above A Daily One Month LIBOR Rate
Debt Disclosure [Line Items]
Basis spread of variable rate				1.40%
Senior notes | 5.50% Senior Notes
Debt Disclosure [Line Items]
Principal amount of debt issued			$ 500,000,000.0
Stated interest rate			5.50%	5.50%
Proceeds from issuance of senior notes, net of issuance costs			$ 488,400,000
Debt issuance costs			$ 11,600,000
Debt redemption percentage price, Specified Price			105.50%
Repurchase price, percentage of principal amount			101.00%
Fair Value | Level 2 | Senior notes | 5.50% Senior Notes
Debt Disclosure [Line Items]
Long term debt, 5.50% Senior Notes				$ 505,150,000	493,440,000
Carrying Value | Level 2 | Senior notes | 5.50% Senior Notes
Debt Disclosure [Line Items]
Long term debt, 5.50% Senior Notes				$ 491,059,000	$ 489,609,000
Minimum | Senior notes | 5.50% Senior Notes
Debt Disclosure [Line Items]
Debt redemption notice period			30 days
Maximum | Senior notes | 5.50% Senior Notes
Debt Disclosure [Line Items]
Debt redemption notice period			60 days
Percentage of debt redeemed			35.00%
Subsequent event
Debt Disclosure [Line Items]
EBITDA	3.25