DEBT (Debt) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017		Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Debt Instrument [Line Items]
Total short-term debt		$ 0				$ 0
Total long-term debt - face value		2,881,529,000				2,004,065,000
Unamortized discounts and debt issuance costs		(26,664,000)				(21,176,000)
Total long-term debt - book value		2,854,865,000				1,982,889,000
Less current maturities		41,383,000				138,000
Total long-term debt - reported value		2,813,482,000				1,982,751,000
Estimated fair value of long-term debt		2,983,419,000				2,243,213,000
Bank Line of Credit [Member]
Debt Instrument [Line Items]
Total short-term debt	[1],[2]	0				0
Bank Line of Credit [Member]
Debt Instrument [Line Items]
Total long-term debt - face value	[1],[2]	$ 250,000,000				235,000,000
Maturity date		Dec. 31, 2021
Effective interest rate	[1],[2]	1.25%
Term Loan Due 2018 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value	[2],[3]	$ 350,000,000				0
Maturity year		2018
Effective interest rate	[2],[3]	2.96%
Notes [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 2,631,529,000
Notes [Member] | 10.125% notes due 2015 [Member]
Debt Instrument [Line Items]
Interest rate								10.125%
Maturity year		2015
Notes [Member] | 7.00% notes due 2018 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 0		$ 272,512,000		$ 272,512,000
Interest rate				7.00%		7.00%		7.00%
Maturity year		2018
Notes [Member] | 10.375% notes due 2018 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 0		$ 250,000,000		$ 250,000,000
Interest rate				10.375%		10.375%
Maturity year		2018
Notes [Member] | Floating-Rate Notes Due 2020 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 250,000,000				$ 0
Maturity year		2020
Effective interest rate		2.22%
Notes [Member] | 7.50% notes due 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 35,111,000				$ 600,000,000
Interest rate		7.50%				7.50%
Maturity year		2021
Effective interest rate		7.75%
Notes [Member] | 8.85% notes due 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 6,000,000				$ 6,000,000
Interest rate		8.85%				8.85%
Maturity year		2021
Effective interest rate		8.88%
Notes [Member] | Delayed draw term loan [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 250,000,000	[2]	$ 250,000,000		$ 0	[2]
Maturity year		2021
Effective interest rate	[2]	2.75%
Notes [Member] | 4.50% notes due 2025 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 400,000,000				$ 400,000,000
Interest rate		4.50%				4.50%		4.50%
Maturity year		2025
Effective interest rate		4.65%
Notes [Member] | 3.90% notes due 2027 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 400,000,000				$ 0
Interest rate		3.90%		3.90%	3.90%
Maturity year		2027
Effective interest rate		4.00%
Notes [Member] | 7.15% notes due 2037 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 240,188,000				$ 240,188,000
Interest rate		7.15%				7.15%
Maturity year		2037
Effective interest rate		8.05%
Notes [Member] | 4.50% notes due 2047 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 700,000,000				$ 0
Interest rate		4.50%		4.50%
Maturity year		2047
Effective interest rate		4.59%
Other Notes [Member]
Debt Instrument [Line Items]
Total long-term debt - face value	[2]	$ 230,000				$ 365,000
Effective interest rate	[2]	6.46%

[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] This short-term loan was refinanced on a long-term basis in February 2018 as discussed below