DEBT (Details) - USD ($)			1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	May 02, 2016	May 09, 2011	May 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2016
Debt Disclosure [Line Items]
Proceeds from issuance of senior notes, net of issuance costs						$ 0	$ 488,401,000
Initiation date of credit agreement		May 09, 2011
Amendment date of Credit Agreement	May 02, 2016
Credit facility expiration date						May 09, 2019
Commitment fee percentage						0.37%
Outstanding borrowings under line of credit				$ 0		$ 0		$ 0
Minimum required liquid funds						300,000,000.0
Restructuring charges (credits)				$ 113,000	$ 8,433,000	$ (1,350,000)	$ 8,433,000	16,200,000
Line Of Credit Facility Interest Rate Spread Below The Banks Announced Prime Rate [Member]
Debt Disclosure [Line Items]
Spread for interest rate						1.20%
Line Of Credit Facility Interest Rate Spread Above A Daily One Month LIBOR Rate [Member]
Debt Disclosure [Line Items]
Spread for interest rate						1.40%
Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Principal amount of debt issued			$ 500,000,000.0
Stated interest rate of debt instrument			5.50%	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%
Minimum [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Debt redemption notice period			30 days
Maximum [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Debt redemption notice period			60 days
Percentage of debt redeemed			35.00%
Level 2 [Member] | Fair Value [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Long-term debt, 5.50% Senior Notes				$ 507,105,000		$ 507,105,000		493,440,000
Level 2 [Member] | Carrying Value [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Long-term debt, 5.50% Senior Notes				$ 490,696,000		$ 490,696,000		$ 489,609,000
Revolving Credit Facility [Member]
Debt Disclosure [Line Items]
Maximum borrowing capacity of unsecured revolving credit facility	$ 100,000,000.0