Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net earnings	$ 18,446	$ 5,757
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	21,150	21,008
Equity-based compensation expense	2,172	1,169
Deferred tax expense	4,365	(1,330)
Employee benefit plans	(1,389)	809
Amortization of Financing Costs and Discounts	213	178
Gain (Loss) on Disposition of Assets	0	(30)
Other Noncash Income Tax Expense	(151)	(990)
Changes in working capital, net	(9,548)	3,457
Change in taxes receivable, net	14,172	1,255
Excess tax benefits from equity share-based payment arrangements	0	343
Funding of qualified pension plans	0	(1,561)
Other Operating Activities, Cash Flow Statement	(408)	(1,327)
Net cash provided by operating activities	49,022	28,052
CASH FLOWS FROM INVESTING ACTIVITIES
Change in short-term investments, net	250	39,000
Additions to plant and equipment	(30,955)	(25,240)
Proceeds from Sale of Productive Assets	0	506
Net cash used for investing activities	(30,705)	14,266
CASH FLOWS FROM FINANCING ACTIVITIES
Purchase of treasury stock	(27,661)	(37,148)
Proceeds from (Repayments of) Short-term Debt	123,287	0
Payments of Debt Issuance Costs	117,282
Payment of tax withholdings on equity-based payment arrangements	(43)	(3,048)
Excess Tax Benefit from Share-based Compensation, Financing Activities	0	343
Net cash (used for) provided by financing activities	(21,699)	(39,853)
Increase in cash	(3,382)	2,465
Cash at beginning of period	5,610	27,331
Cash at end of period	2,228	29,796
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest, net of amounts capitalized	13,871	14,340
Cash paid for income taxes	742	2,518
Cash received from income tax refunds	10,334	479
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING ACTIVITIES:
Capital Expenditures Incurred but Not yet Paid	$ (5,223)	$ (4,434)