SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) state item factor shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2017 USD ($)
State of incorporation	New Jersey
Number of states | state	20
Number of demographic factors | factor	3
Rabbi Trust asset value, decrease	$ (3,967)
Net gains (losses) of the Rabbi Trust investments	2,741	$ (1,517)	$ 1,169
Unrealized net gains (losses) of the Rabbi Trust investments	$ 1,599	(1,769)	(1,049)
Number of Rabbi Trust estabished | item	2
Number of Facilities | item	8
Bad debt expense	$ (1,190)	1,450	2,031
Write-offs of accounts receivables	1,544	1,483	2,561
Capitalized software costs	4,732	7,003
Capitalized software costs during the year	152	1,482	921
Goodwill	3,094,824	3,094,824	3,094,824
Loss on impairment of long-lived assets	10,506	5,190	3,095
Assets, Fair Value Disclosure, Nonrecurring	$ 0	$ 0
Percentage of goodwill in total assets	37.00%	37.00%
Percentage of net property, plant & equipment in total assets	39.00%
Percentage of net other intangible assets in total assets	9.00%
Number of Reporting Units | item	18
Proceeds from sale of future production				$ 153,282	$ 73,644
Amortization term of proceeds from sale of future production	25 years
Stripping costs	$ 55,987	$ 50,409	44,896
Capitalized pre-production stripping costs	70,227	61,369
Spread between the amount accrued and the maximum environmental loss	3,341
Maximum self-insurance coverage per occurrence for losses related to workers' compensation	2,000
Maximum self-insurance coverage per occurrence for automotive and general/product liability	$ 3,000
Accounting Standards Codification Topic 740 - Income Taxes recognition threshold for uncertain tax positions	50.00%
Excess tax benefits from share-based compensation	$ 0	18,376	3,464
Gross excess tax benefits from share-based compensation, operating activity	28,009
Operating cash flows	644,588	519,538	261,007
Financing cash flows	(304,585)	(67,009)	(551,803)
Asset Retirement Obligation	$ 223,872	226,594	226,565
LIFO method used for percentage of inventory	66.00%
Goodwill [Member]
Number of Reporting Units | item	9
Accounting Standards Update 2016-09 [Member]
Tax reduction from net excess tax benefits from share based compensation	$ 24,847
Increase in dilutive shares | shares	773,101
Minimum [Member] | Machinery and Equipment [Member]
Estimated service lives	3 years
Minimum [Member] | Buildings [Member]
Estimated service lives	7 years
Minimum [Member] | Land Improvements [Member]
Estimated service lives	8 years
Maximum [Member] | Machinery and Equipment [Member]
Estimated service lives	25 years
Maximum [Member] | Buildings [Member]
Estimated service lives	20 years
Maximum [Member] | Land Improvements [Member]
Estimated service lives	20 years
Forecast [Member]
Estimated deferred revenue to be recognized in the next 12 months						$ 8,080
Restatement Adjustment [Member]
Operating cash flows		16,160	671
Financing cash flows		$ (16,160)	$ (671)