LONG-TERM DEBT (Break-Down of Long-Term Debt) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Net unamortized debt issuance costs	$ (26,052)	$ (30,733)
Less: current maturities of long term debt	(622)	(651)
Long-term debt, net of current maturities	2,076,569	2,086,765
Construction loan
Debt Instrument [Line Items]
Net unamortized debt issuance costs	(100)
6.625% senior unsecured notes due 2023 \| Senior notes
Debt Instrument [Line Items]
Long-term debt	340,000	350,000
Net unamortized debt issuance costs	$ (3,600)
Stated interest rate, percent	6.625%
6.000% senior unsecured notes due 2024 \| Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 630,796	650,000
Net unamortized debt issuance costs	$ (7,500)
Stated interest rate, percent	6.00%
6.375% senior unsecured notes due 2025 \| Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 577,268	600,000
Net unamortized debt issuance costs	$ (10,800)
Stated interest rate, percent	6.375%
6.375% senior unsecured notes due 2026 \| Senior notes
Debt Instrument [Line Items]
Long-term debt	$ 397,529	450,000
Net unamortized debt issuance costs	$ (4,000)
Stated interest rate, percent	6.375%
Nova Scotia, Amegy, KeyBank \| Revolving credit agreement \| Revolving credit agreement
Debt Instrument [Line Items]
Long-term debt	$ 135,000	45,000
InterBank \| Letter of credit \| Construction loan
Debt Instrument [Line Items]
Long-term debt	$ 22,650	$ 23,149

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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