ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Changes in accumulated other comprehensive income
Balance			$ 1,514,223
Other comprehensive income (loss)	$ (1,962)	$ (1,440)	(11,698)	$ 533
Balance	1,515,247		1,515,247
Accumulated Other Comprehensive Income (Loss)
Changes in accumulated other comprehensive income
Balance			12,844	24,204
Other comprehensive income (loss) before reclassifications			(1,033)	1,555
Amounts reclassified from accumulated other comprehensive income			(10,665)	(1,022)
Other comprehensive income (loss)			(11,698)	533
Balance	1,146	24,737	1,146	24,737
Foreign Currency
Changes in accumulated other comprehensive income
Balance			627	(351)
Other comprehensive income (loss) before reclassifications	700	1,090	981	657
Other comprehensive income (loss)			981	657
Balance	1,608	306	1,608	306
Pension and Other Benefits (recorded in G&A : Other)
Changes in accumulated other comprehensive income
Balance			5,564	20,967
Other comprehensive income (loss) before reclassifications			701
Amounts reclassified from accumulated other comprehensive income			(10,862)	(1,394)
Other comprehensive income (loss)			(10,161)	(1,394)
Balance	(4,597)	19,573	(4,597)	19,573
Unrealized Gains on Marketable Securities (Recorded in Investment income)
Changes in accumulated other comprehensive income
Balance			3,812	1,216
Other comprehensive income (loss) before reclassifications	(2,311)	(2,597)	(1,868)	762
Amounts reclassified from accumulated other comprehensive income	(5)	(10)	(154)	(25)
Other comprehensive income (loss)			(2,022)	737
Balance	1,790	1,953	1,790	1,953
Unrealized Gain from Equity Method Investees' Cash Flow Hedge
Changes in accumulated other comprehensive income
Balance			2,841	2,372
Other comprehensive income (loss) before reclassifications	(465)	408	(847)	136
Amounts reclassified from accumulated other comprehensive income	112	134	351	397
Other comprehensive income (loss)			(496)	533
Balance	$ 2,345	$ 2,905	$ 2,345	$ 2,905