FINANCIAL INSTRUMENTS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Customer No 1 [Member] | Consolidated Revenues [Member]
Concentrations of Credit Risk [Abstract]
Customer concentration, percentage of consolidated revenues	26.00%	29.00%	29.00%
Customer No 2 [Member] | Consolidated Revenues [Member]
Concentrations of Credit Risk [Abstract]
Customer concentration, percentage of consolidated revenues	11.00%	11.00%	21.00%
Customer No 3 [Member] | Consolidated Revenues [Member]
Concentrations of Credit Risk [Abstract]
Customer concentration, percentage of consolidated revenues			11.00%
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	$ 2,117,474	$ 2,230,646
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	2,008,700	2,009,598
5% Senior Notes, due 2017 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	433,879	445,568
5% Senior Notes, due 2017 [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	398,961	398,678
7.875% Senior Notes due 2019 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	603,177	617,076
7.875% Senior Notes due 2019 [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	498,171	497,842
4.875% Senior Notes due 2022 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	711,816	761,509
4.875% Senior Notes due 2022 [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	713,208	714,775
5.4% Senior Notes, due 2042 [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	368,602	406,493
5.4% Senior Notes, due 2042 [Member] | Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior Notes	$ 398,360	$ 398,303