Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Purchase of common stock	$ (11,184)	$ (10,818)
Withholding taxes paid for conversion of employee stock awards	(1,436)	(1,231)
OPERATING ACTIVITIES:
Net earnings (loss) from continuing operations	(44,122)	19,699
Net earnings from discontinued operations	(384)	(94)
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	80,097	66,600
Pension and post-retirement	3,990	6,764
Deferred income taxes	11,454	10,969
Amortization of stock-based compensation	1,710	1,575
Net (gain) loss on financial instruments	155	315
Changes in assets and liabilities:
Accounts receivable	1,905	6,376
Inventory and prepaid supplies	(1,822)	(1,560)
Accounts payable	14,244	(2,552)
Unearned revenue	1,807	(3,141)
Accrued expenses, salaries, wages, benefits and other liabilities	(6,793)	(638)
Pension and post-retirement assets	(5,847)	(3,881)
Other	1,991	2,018
NET CASH PROVIDED BY OPERATING ACTIVITIES	124,778	97,293
INVESTING ACTIVITIES:
Capital expenditures	(144,325)	(125,076)
Investment in nonconsolidated affiliate	(646)	0
NET CASH (USED IN) INVESTING ACTIVITIES	(134,996)	(125,076)
FINANCING ACTIVITIES:
Principal payments on long term obligations	(20,500)	(12,623)
Proceeds from borrowings	90,000	60,000
NET CASH PROVIDED BY FINANCING ACTIVITIES	56,880	35,328
NET INCREASE IN CASH AND CASH EQUIVALENTS	46,662	7,545
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	16,358	17,697
CASH AND CASH EQUIVALENTS AT END OF PERIOD	63,020	25,242
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid, net of amount capitalized	7,101	5,104
Federal alternative minimum and state income taxes paid	1,220	464
SUPPLEMENTAL NON-CASH INFORMATION:
Accrued capital expenditures	12,615	5,923
Net (gain) loss on financial instruments	(65,780)	5,030
Redemption of long term deposits	$ 9,975	$ 0