DEBT (Narrative) (Details) - USD ($)		1 Months Ended					3 Months Ended		6 Months Ended
		Dec. 31, 2015	Aug. 31, 2015	Jun. 30, 2015	Apr. 30, 2015	Mar. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2011
Debt Instrument [Line Items]
Net interest expense									$ 2,203,000
Transaction fees									$ 0	$ 7,382,000
Debt to EBITDA ratio									3.5
EBITDA to net cash interest expense ratio									3.0
Long term debt		$ 1,980,464,000		$ 1,907,861,000			$ 1,907,861,000		$ 1,982,658,000	1,907,861,000
Debt instrument face amount		2,004,198,000		2,071,813,000			2,071,813,000		2,004,189,000	2,071,813,000
Total consideration paid for debt					$ 385,024,000				9,000	530,945,000
Premium paid for purchase of debt					41,153,000
Transaction cost related to termination of debt					52,000
Other cost (benefit) related to debt purchase					$ 4,136,000
Cost of debt purchase							45,341,000		$ 0	67,075,000
Period of letters of credit									1 year
10.125% notes due 2015 [Member]
Debt Instrument [Line Items]
Long term debt		0		150,000,000			150,000,000		$ 0	150,000,000
Repayments of debt		150,000,000
Interest rate									10.125%		10.125%
Maturity year									2015
4.50% notes due 2025 [Member]
Debt Instrument [Line Items]
Long term debt		400,000,000		400,000,000			400,000,000		$ 400,000,000	400,000,000
Debt instrument face amount						$ 400,000,000		$ 400,000,000
Interest rate						4.50%		4.50%	4.50%
Maturity year								2025	2025
Debt issued, net proceeds						$ 395,207,000
7.00% notes due 2018 [Member]
Debt Instrument [Line Items]
Long term debt		272,512,000		272,512,000			272,512,000		$ 272,512,000	272,512,000
Interest rate					7.00%	7.00%		7.00%	7.00%
Maturity year					2018			2018	2018
Debt purchased, amount					$ 185,000	$ 127,303,000		$ 127,303,000
Principal amount, percentage					1.00%	32.00%
Total consideration paid for debt						$ 145,899,000
Premium paid for purchase of debt						18,140,000		18,140,000
Transaction cost related to termination of debt						456,000
Other cost (benefit) related to debt purchase						$ 3,138,000
Cost of debt purchase								$ 21,734,000
6.40% notes due 2017 [Member]
Debt Instrument [Line Items]
Long term debt		0		0			0		$ 0	0
Interest rate					6.40%				6.40%
Maturity year					2017				2017
Debt purchased, amount					$ 218,633,000
Principal amount, percentage					100.00%
6.50% notes due 2016 [Member]
Debt Instrument [Line Items]
Long term debt		0		0			0		$ 0	0
Debt instrument face amount											$ 500,000,000
Interest rate					6.50%				6.50%		6.50%
Maturity year					2016				2016
Debt purchased, amount					$ 125,001,000
Principal amount, percentage					100.00%
Bank Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity				500,000,000			500,000,000		$ 750,000,000	500,000,000
Transaction fees				2,589,000
Line of credit, expiration date									Jun. 01, 2020
Commitment fee									0.15%
Available borrowing capacity									$ 475,160,000
Long term debt									$ 235,000,000
Bank Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									1.25%
Bank Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									0.25%
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Other liabilities									$ 39,840,000
Standby Letters of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									0.175%
Minimum [Member] | Bank Line of Credit [Member]
Debt Instrument [Line Items]
Commitment fee									0.10%
Minimum [Member] | Bank Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									1.00%
Minimum [Member] | Bank Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									0.00%
Maximum [Member] | Bank Line of Credit [Member]
Debt Instrument [Line Items]
Commitment fee									0.35%
Maximum [Member] | Bank Line of Credit [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									2.00%
Maximum [Member] | Bank Line of Credit [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									1.00%
Other Notes [Member]
Debt Instrument [Line Items]
Long term debt	[1]	498,000		613,000			613,000		$ 489,000	613,000
Industrial Revenue Bonds [Member]
Debt Instrument [Line Items]
Long term debt		$ 0		$ 14,000,000			$ 14,000,000		$ 0	$ 14,000,000
Repayments of debt			$ 14,000,000
Maturity year									2022

[1] Non-publicly traded debt.