SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2017

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES [Abstract]

Depreciation, Depletion, Accretion and Amortization Expense

in thousands	2017	2016	2015
Depreciation, Depletion, Accretion and Amortization
Depreciation	$      250,835	$     238,237	$     228,866
Depletion	19,342	17,812	18,177
Accretion	11,415	11,059	11,474
Amortization of leaseholds	608	267	688
Amortization of intangibles	23,765	17,565	15,618
Total	$      305,965	$     284,940	$     274,823

Fair Value Measurement on Recurring Basis

	Level 1 Fair Value
in thousands	2017	2016
Fair Value Recurring
Rabbi Trust
Mutual funds	$       20,348	$       6,883
Equities	0	10,033
Total	$       20,348	$     16,916

	Level 2 Fair Value
in thousands	2017	2016
Fair Value Recurring
Rabbi Trust
Money market mutual fund	$        1,203	$       1,705
Total	$        1,203	$       1,705

Fair Value Measurement on Nonrecurring Basis

	Year ending December 31, 2017		Year ending December 31, 2016
		Impairment		Impairment
in thousands	Level 2	Charges	Level 2	Charges
Fair Value Nonrecurring
Property, plant & equipment	$              0	$             0	$             0	$      1,359
Other intangible assets, net	0	0	0	8,180
Other assets	0	0	0	967
Totals	$              0	$             0	$             0	$    10,506

Reconciliation of Deferred Revenue Balances

in thousands	2017	2016	2015
Deferred Revenue
Balance at beginning of year	$      206,468	$     214,060	$     219,968
Amortization of deferred revenue	(6,912)	(7,592)	(5,908)
Balance at end of year	$      199,556	$     206,468	$     214,060

Unrecognized Compensation Expense

	Unrecognized	Expected
	Compensation	Weighted-average
dollars in thousands	Expense	Recognition (Years)
Share-based Compensation
SOSARs 1	$          4,623	1.5
Performance shares	18,424	1.8
Restricted shares	5,244	2.6
Total/weighted-average	$        28,291	1.9

1 Stock-Only Stock Appreciation Rights (SOSARs)

Pretax Compensation Expense

in thousands	2017	2016	2015
Employee Share-based Compensation Awards
Pretax compensation expense	$        24,367	$       17,823	$       16,362
Income tax benefits	6,226	6,925	6,347

Liabilities Under Self-Insurance Program

dollars in thousands	2017	2016
Self-insurance Program
Self-insured liabilities (undiscounted)	$        58,216	$       49,310
Insured liabilities (undiscounted)	7,892	72,644
Discount rate	1.93%	1.40%
Amounts Recognized in Consolidated
Balance Sheets
Other accounts and notes receivable	$          6,158	$       67,631
Investments and long-term receivables	7,246	16,133
Other current liabilities	(20,036)	(69,549)
Other noncurrent liabilities	(41,792)	(49,074)
Net liabilities (discounted)	$       (48,424)	$     (34,859)

Estimated Payments (Undiscounted) Under Self-Insurance Program

in thousands
Estimated Payments under Self-insurance Program
2018	$        22,697
2019	11,874
2020	7,856
2021	4,709
2022	3,088

Weighted-Average Common Shares Outstanding Assuming Dilution

in thousands	2017	2016	2015
Weighted-average common shares outstanding	132,513	133,205	133,210
Dilutive effect of
SOSARs	1,295	1,339	1,027
Other stock compensation plans	1,070	1,246	856
Weighted-average common shares outstanding,
assuming dilution	134,878	135,790	135,093

Antidilutive Common Stock Equivalents

in thousands	2017	2016	2015
Antidilutive common stock equivalents	79	97	544