DEBT (Summary of Debt Additional Information) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2015	Apr. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Jun. 30, 2011
Debt Instrument [Line Items]
Debt instrument face amount		$ 2,004,198,000			$ 2,004,459,000		$ 500,000,000
10.125% notes due 2015 [Member]
Debt Instrument [Line Items]
Interest rate		10.125%			10.125%
Maturity year		2015
6.50% notes due 2016 [Member]
Debt Instrument [Line Items]
Interest rate		6.50%	6.50%		6.50%	6.50%	6.50%
Maturity year		2016
6.40% notes due 2017 [Member]
Debt Instrument [Line Items]
Interest rate		6.40%	6.40%		6.40%	6.40%
Maturity year		2017
7.00% notes due 2018 [Member]
Debt Instrument [Line Items]
Interest rate		7.00%	7.00%	7.00%
Maturity year		2018
Effective interest rate		7.87%
10.375% notes due 2018 [Member]
Debt Instrument [Line Items]
Interest rate		10.375%			10.375%
Maturity year		2018
Effective interest rate		10.63%
7.50% notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate		7.50%			7.50%
Maturity year		2021
Effective interest rate		7.75%
8.85% notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate		8.85%			8.85%
Maturity year		2021
Effective interest rate		8.88%
4.50% notes due 2025 [Member]
Debt Instrument [Line Items]
Interest rate		4.50%		4.50%
Maturity year		2025
Debt instrument face amount				$ 400,000,000
Effective interest rate		4.65%
7.15% notes due 2037 [Member]
Debt Instrument [Line Items]
Interest rate		7.15%			7.15%
Maturity year		2037
Effective interest rate		8.05%
Bank Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit, expiration date		Jun. 01, 2020
Bank Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit, expiration date		Jun. 01, 2020
Effective interest rate	[1],[2],[3]	1.75%
Industrial Revenue Bonds [Member]
Debt Instrument [Line Items]
Maturity year		2022
Other Notes [Member]
Debt Instrument [Line Items]
Effective interest rate	[2]	6.25%

[1] Borrowings on the bank line of credit are classified as short-term debt if we intend to repay within twelve months and as long-term debt otherwise.

[2] Non-publicly traded debt.

[3] The effective interest rate is the spread over LIBOR as of the balance sheet dates.