INCOME TAXES (Components of Net Deferred Income Tax Liability) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
INCOME TAXES [Abstract]
Pensions	$ 24,185	$ 84,869
Other postretirement benefits	35,752	44,030
Asset retirement obligations and environmental accruals	41,725	40,202
Accounts receivable, principally allowance for doubtful accounts	1,279	1,910
Deferred compensation, vacation pay and incentives	108,147	102,048
Interest rate swaps	17,371	19,585
Self-insurance reserves	18,338	18,165
Inventory	8,866	8,011
Federal net operating loss carryforwards	65,420	57,679
State net operating loss carryforwards	53,946	45,929
Valuation allowance on state net operating loss carryforwards	(46,280)	(38,837)
Foreign tax credit carryforwards	22,410	22,409
Alternative minimum tax credit carryforwards	16,489	15,711
Charitable contribution carryforwards	10,814	9,953
Other	14,775	20,561
Total deferred tax assets	393,237	452,225
Fixed assets	725,162	754,697
Intangible assets	304,972	295,429
Other	23,755	18,770
Total deferred tax liabilities	1,053,889	1,068,896
Net deferred tax liability	$ 660,652	$ 616,671