Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash Flows from Operating Activities:
Consolidated net earnings	$ 36,472	$ 12,238
Adjustments to reconcile consolidated net earnings to net cash provided by operating activities:
Depreciation, depletion and amortization	86,147	85,992
Stock-based compensation expense	4,370	3,981
Gains on divestitures and sales of assets	(1,747)	(422)
Deferred income taxes	(6,433)	9,282
Excess tax benefits from stock-based compensation transactions	(1,922)	(2,253)
Other items, net	3,227	(530)
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Accounts receivable, net	(98,911)	(65,165)
Inventories, net	(4,269)	(15,838)
Accounts payable	35,842	16,423
Other assets and liabilities, net	17,587	4,764
Net Cash Provided by Operating Activities	70,363	48,472
Cash Flows from Investing Activities:
Additions to property, plant and equipment	(84,737)	(50,002)
Acquisitions, net	(117)	(3,246)
Proceeds from divestitures and sales of assets	2,154	1,874
Repayments from affiliate	529
Payment of railcar construction advances	(14,513)
Reimbursement of railcar construction advances	14,513
Net Cash Used for Investing Activities	(82,171)	(51,374)
Cash Flows from Financing Activities:
Borrowings of long-term debt	100,000	295,500
Repayments of long-term debt	(46,417)	(250,167)
Payments on capital lease obligations	(1,052)
Debt issuance costs	(881)	(510)
Change in bank overdraft	(2,556)
Dividends paid	(37,254)	(37,068)
Purchase of remaining interest in existing subsidiaries	(19,604)
Issuances of common stock	9,542	11,212
Excess tax benefits from stock-based compensation transactions	1,922	2,253
Net Cash Provided by Financing Activities	3,700	21,220
Net (Decrease) Increase in Cash and Cash Equivalents	(8,108)	18,318
Cash and Cash Equivalents, beginning of period	42,437	25,394
Cash and Cash Equivalents, end of period	34,329	43,712
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	25,173	25,868
Cash paid (received) for income taxes	$ 3,511	$ (6,103)