Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash Flows from Operating Activities:
Consolidated net earnings	$ 336,087	$ 326,647
Adjustments to reconcile consolidated net earnings to net cash provided by operating activities:
Depreciation, depletion and amortization	221,418	211,997
Stock-based compensation expense	23,698	17,167
(Gain) Loss on divestitures and sales of assets	(17,970)	158
Deferred income taxes	6,543	59,834
Other items, net	(9,618)	(17,797)
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Accounts receivable, net	(124,622)	(133,848)
Inventories, net	(54,804)	(33,956)
Accounts payable	3,182	12,422
Other assets and liabilities, net	34,484	(20,911)
Net Cash Provided by Operating Activities	418,398	421,713
Cash Flows from Investing Activities:
Additions to property, plant and equipment	(308,745)	(285,481)
Acquisitions, net	(7,200)	(178,689)
Cash received in acquisition		4,246
Proceeds from divestitures and sales of assets	33,138	5,216
Payment of railcar construction advances	(42,954)	(37,370)
Reimbursement of railcar construction advances	40,930	37,370
Net Cash Used for Investing Activities	(284,831)	(454,708)
Cash Flows from Financing Activities:
Borrowings of debt	1,011,244	360,000
Repayments of debt	(975,035)	(168,267)
Payments on capital lease obligations	(2,708)	(2,463)
Debt issuance costs	(1,989)	(213)
Change in bank overdraft	1,047	(10,235)
Contributions by owners of noncontrolling interest	211
Dividends paid	(80,961)	(78,295)
Proceeds from exercise of stock options	10,017	21,876
Shares withheld for employees' income tax obligations	(10,213)	(7,133)
Repurchases of common stock	(99,999)	(190,000)
Net Cash Used for Financing Activities	(148,386)	(74,730)
Net Decrease in Cash and Cash Equivalents	(14,819)	(107,725)
Cash and Cash Equivalents, beginning of period	50,038	168,409
Cash and Cash Equivalents, end of period	$ 35,219	$ 60,684