CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
Net (loss) income	$ (63,749)	$ 162,040
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, amortization and other non-cash charges	132,515	123,281
Stock-based compensation expense	7,324	7,204
Gain on disposition of assets, net	(2,910)	(3,459)
Gain due to insurance recovery		(9,646)
Gain due to benefit financing arrangement	(126)	(1,020)
Deferred income tax (benefit) provision	(21,777)	6,319
Impairment and other non-cash charges	71,650
(Increase) decrease in assets:
Accounts receivable	35,052	(5,029)
Income taxes receivable	15,061	28,664
Inventories	17,713	(14,233)
Prepaid expenses	2,472	2,647
Other current assets	263	1,420
Other non-current assets	(3,850)	(2,106)
Increase (decrease) in liabilities:
Accounts payable	(24,125)	21,852
Income taxes payable	(3,857)	1,775
Accrued payroll and related expenses	(1,711)	8,583
Accrued insurance expenses	306	604
Accrued state, local and other taxes	4,287	(1,545)
Other accrued expenses	(1,815)	(873)
Pension liabilities	4,627	(4,700)
Long-term accrued insurance expenses	1,471	1,059
Other long-term liabilities	892	(885)
Net cash provided by operating activities	169,713	321,952
INVESTING ACTIVITIES
Capital expenditures	(209,263)	(199,581)
Proceeds from sale of assets	12,394	10,102
Proceeds from insurance recovery		9,646
Proceeds from benefit plan financing arrangement	507	2,218
Re-investment in benefit plan financing arrangement	(507)	(2,218)
Net cash used for investing activities	(196,869)	(179,833)
FINANCING ACTIVITIES
Payment of dividends	(32,224)	(64,636)
Cash paid for common stock purchased and retired	(7,359)	(40,160)
Net cash used for financing activities	(39,583)	(104,796)
Net (decrease) increase in cash and cash equivalents	(66,739)	37,323
Cash and cash equivalents at beginning of period	116,262	91,050
Cash and cash equivalents at end of period	49,523	128,373
Supplemental cash flows disclosure:
Income taxes (refund) paid, net	(10,826)	1,781
Supplemental disclosure of noncash investing activities:
Capital expenditures included in accounts payable	$ 18,345	$ 8,960