Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Purchase of common stock	$ (3,581)	$ (11,184)
Withholding taxes paid for conversion of employee stock awards	1,329	1,436
OPERATING ACTIVITIES:
Net earnings (loss) from continuing operations	40,146	(44,122)
Net earnings from discontinued operations	366	384
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	94,270	80,097
Pension and post-retirement	1,884	3,990
Deferred income taxes	10,475	11,454
Amortization of stock-based compensation	2,304	1,710
Net (gain) loss on financial instruments	(3,152)	154
Changes in assets and liabilities:
Accounts receivable	11,006	1,905
Inventory and prepaid supplies	3,433	(1,822)
Accounts payable	(2,067)	14,244
Unearned revenue	(1,504)	1,807
Accrued expenses, salaries, wages, benefits and other liabilities	(3,406)	(6,793)
Pension and post-retirement assets	(8,323)	(5,847)
Other	4,211	1,991
NET CASH PROVIDED BY OPERATING ACTIVITIES	141,983	124,778
INVESTING ACTIVITIES:
Capital expenditures	(150,816)	(144,325)
Proceeds from property and equipment	17,452	0
Investment in nonconsolidated affiliate	(5,150)	(646)
Redemption of long term deposits	0	9,975
NET CASH (USED IN) INVESTING ACTIVITIES	(138,514)	(134,996)
FINANCING ACTIVITIES:
Principal payments on long term obligations	(29,140)	(20,500)
Proceeds from borrowings	30,000	90,000
Payments for financing costs	(414)	0
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	(4,464)	56,880
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(995)	46,662
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	32,699	16,358
CASH AND CASH EQUIVALENTS AT END OF PERIOD	31,704	63,020
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid, net of amount capitalized	6,450	7,101
Federal alternative minimum and state income taxes paid	806	1,220
SUPPLEMENTAL NON-CASH INFORMATION:
Accrued capital expenditures	18,755	12,615
Net (gain) loss on financial instruments	$ 10,812	$ (65,780)