DEBT (Narrative) (Details)		1 Months Ended				3 Months Ended			6 Months Ended
		Oct. 31, 2016	Apr. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Jun. 30, 2011 USD ($)
Debt Instrument [Line Items]
Interest Expense, Long-term Debt									$ 2,067,000
Debt purchased, amount					$ 506,366,000			$ 506,366,000
Total consideration paid for debt					579,659,000	$ 385,024,000			676,445,000	$ 579,694,000
Premium paid for purchase of debt					$ 71,829,000	41,153,000		71,829,000	41,153,000
Transaction cost related to termination of debt						52,000		1,464,000
Other cost (benefit) related to debt purchase						4,136,000		(344,000)
Cost of debt purchase						45,341,000		$ 72,949,000	$ 67,075,000	72,949,000
Debt to EBITDA ratio									3.5
EBITDA to net cash interest expense ratio									3.0
Short-term debt (line of credit)						138,500,000			$ 138,500,000	0	$ 0
Long term debt	[1]					$ 1,907,861,000			$ 1,907,861,000	1,983,477,000	1,984,779,000
4.50% notes due 2025 [Member]
Debt Instrument [Line Items]
Debt issued, amount				$ 400,000,000			$ 400,000,000
Interest rate				4.50%		4.50%	4.50%		4.50%
Debt issued, net proceeds				$ 395,207,000
Maturity year							2025		2025
Long term debt						$ 400,000,000			$ 400,000,000	0	0
7.00% notes due 2018 [Member]
Debt Instrument [Line Items]
Interest rate			7.00%			7.00%			7.00%
Maturity year			2018				2018		2018
Debt purchased, amount			$ 185,000	127,303,000			$ 127,303,000
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
Long term debt						$ 272,512,000			$ 272,512,000	400,000,000	400,000,000
Principal amount, percentage									32.00%
6.40% notes due 2017 [Member]
Debt Instrument [Line Items]
Interest rate			6.40%		6.40%	6.40%		6.40%	6.40%
Maturity year			2017					2017	2017
Debt purchased, amount			$ 218,633,000		$ 131,367,000			$ 131,367,000
Long term debt						$ 0			$ 0	218,633,000	218,633,000
Principal amount, percentage									100.00%
6.50% notes due 2016 [Member]
Debt Instrument [Line Items]
Debt issued, amount												$ 500,000,000
Interest rate			6.50%		6.50%	6.50%		6.50%	6.50%			6.50%
Debt purchased, redemption date									Apr. 01, 2015
Maturity year			2016					2016	2016
Debt purchased, amount			$ 125,001,000		$ 374,999,000			$ 374,999,000
Long term debt						$ 0			$ 0	125,001,000	125,001,000
Principal amount, percentage									100.00%
8.85% notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate						8.85%			8.85%
Maturity year									2021
Long term debt						$ 6,000,000			$ 6,000,000	6,000,000	6,000,000
10.125% notes due 2015 [Member]
Debt Instrument [Line Items]
Interest rate						10.125%			10.125%			10.125%
Maturity year									2015
Long term debt	[2]					$ 150,000,000			$ 150,000,000	150,000,000	150,000,000
Other Notes
Debt Instrument [Line Items]
Long term debt	[3]					613,000			$ 613,000	769,000	637,000
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									0.175%
Commitment fee									0.25%
Scenario, Forecast [Member]
Debt Instrument [Line Items]
Debt to EBITDA ratio		3.25
Minimum [Member] | Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Commitment fee									0.10%
Maximum [Member] | Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Commitment fee									0.35%
Industrial revenue bonds [Member]
Debt Instrument [Line Items]
Maturity year									2022
Long term debt	[4]					14,000,000			$ 14,000,000	14,000,000	14,000,000
Subsequent Event [Member] | 6.40% notes due 2017 [Member]
Debt Instrument [Line Items]
Debt purchased, redemption date									Apr. 01, 2015
Bank line of Credit [Member]
Debt Instrument [Line Items]
Facility expiration date									Jun. 01, 2020
Borrowing capacity						558,281,000			$ 558,281,000
Line Of Credit Facility Maximum Borrowing Capacity						750,000,000			750,000,000
Short-term debt (line of credit)	[5]					138,500,000			$ 138,500,000	$ 0	$ 0
Applicable margin on borrowing rate									1.75%
Bank line of Credit [Member] | Cancelled line of Credit [Member]
Debt Instrument [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity						500,000,000			$ 500,000,000
Bank line of Credit [Member] | New line of Credit [Member]
Debt Instrument [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity						$ 750,000,000			$ 750,000,000
Bank line of Credit [Member] | SunTrust Bank [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									0.75%
Bank line of Credit [Member] | Minimum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									1.00%
Bank line of Credit [Member] | Minimum [Member] | SunTrust Bank [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									0.00%
Bank line of Credit [Member] | Maximum [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									2.00%
Bank line of Credit [Member] | Maximum [Member] | SunTrust Bank [Member]
Debt Instrument [Line Items]
Applicable margin on borrowing rate									1.00%

[1] The debt balances as of December 31, 2014 and June 30, 2014 have been adjusted to reflect our early adoption of ASU 2015-03 and related election as disclosed in Note 17.

[2] The 10.125% notes due 2015 are classified as long-term debt (not current maturities) as of June 30, 2015 due to our intent and ability to refinance these notes at maturity using our line of credit.

[3] Non-publicly traded debt.

[4] As of June 30, 2015, we had initiated prepayment; as such, this debt is classified as current maturities of long-term debt.

[5] Borrowings are shown as short-term due to our intent to repay within twelve months. The effective interest rate reflects the margin added to LIBOR for LIBOR-based borrowings. We also pay fees for unused borrowing capacity and standby letters of credit.