DEBT (Debt) (Details) - USD ($)		9 Months Ended
		Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Apr. 30, 2015	Mar. 31, 2015
Debt Instrument [Line Items]
Total short-term debt		$ 0	$ 0	$ 0
Total long-term debt - face value		2,004,184,000	2,004,198,000	2,004,203,000
Unamortized discounts and debt issuance costs		(20,414,000)	(23,734,000)	(24,821,000)
Total long-term debt - book value		1,983,770,000	1,980,464,000	1,979,623,000
Less current maturities		131,000	130,000	130,000
Total long-term debt - reported value		1,983,639,000	1,980,334,000	1,979,493,000
Estimated fair value of long-term debt		2,305,065,000	2,204,816,000	2,191,361,000
10.125% notes due 2015 [Member]
Debt Instrument [Line Items]
Unamortized deferred interest rate swap gain	[1]	0	0	241,000
Bank Line of Credit [Member]
Debt Instrument [Line Items]
Total short-term debt	[2],[3],[4]	0	0	0
Bank Line of Credit [Member]
Debt Instrument [Line Items]
Total long-term debt - face value	[2],[3],[4]	$ 235,000,000	235,000,000	85,000,000
Maturity date		Jun. 01, 2020
Effective interest rate	[2],[3],[4]	1.25%
Notes [Member] | 10.125% notes due 2015 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 0	0	150,000,000
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		$ 272,512,000	272,512,000	272,512,000
Interest rate		7.00%			7.00%	7.00%
Maturity year		2018
Effective interest rate		7.87%
Notes [Member] | 10.375% notes due 2018 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 250,000,000	250,000,000	250,000,000
Interest rate		10.375%
Maturity year		2018
Effective interest rate		10.63%
Notes [Member] | 7.50% notes due 2021 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 600,000,000	600,000,000	600,000,000
Interest rate		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	6,000,000
Interest rate		8.85%
Maturity year		2021
Effective interest rate		8.88%
Notes [Member] | 4.50% notes due 2025 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 400,000,000	400,000,000	400,000,000
Interest rate		4.50%				4.50%
Maturity year		2025
Effective interest rate		4.65%
Notes [Member] | 7.15% notes due 2037 [Member]
Debt Instrument [Line Items]
Total long-term debt - face value		$ 240,188,000	240,188,000	240,188,000
Interest rate		7.15%
Maturity year		2037
Effective interest rate		8.05%
Other Notes [Member]
Debt Instrument [Line Items]
Total long-term debt - face value	[3]	$ 484,000	$ 498,000	$ 503,000
Effective interest rate	[3]	6.24%

[1] The unamortized deferred gain was realized upon the August 2011 settlement of interest rate swaps as described in Note 6.

[2] 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.

[3] Non-publicly traded debt.

[4] The effective interest rate is the spread over LIBOR as of the most recent balance sheet date.