Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Operating activities:
Net income	$ 35,790	$ 42,977
Income (loss) from discontinued operations, net of tax	(100)	448
Income from continuing operations	35,890	42,529
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	85,380	84,674
Earnings, net of distributions, from equity method investments	1,181	(484)
Deferred income taxes	32,596	34,502
Changes in current assets and liabilities, net of acquisitions:
Receivables	101,917	50,260
Inventories	(38,357)	(13,634)
Other current assets	(21,556)	(18,897)
Accounts payable	(29,851)	(21,875)
Other current liabilities	(33,751)	(15,738)
Other noncurrent changes	(8,349)	(20,510)
Net cash provided by continuing operations	125,100	120,827
Net cash used in discontinued operations	(107)	(366)
Net cash provided by operating activities	124,993	120,461
Investing activities:
Capital expenditures	(174,429)	(82,664)
Acquisitions, net of cash acquired	(242)	(157)
Net proceeds from sale or disposition of property and other	18,256	10,524
Investments	(27)	(9,856)
Net cash used in continuing operations	(156,442)	(82,153)
Net cash provided by discontinued operations	0	0
Net cash used in investing activities	(156,442)	(82,153)
Financing activities:
Repayment of short-term borrowings	0	(20,000)
Repayment of long-term debt	(8,297)	(80,630)
Proceeds from issuance of common stock	88	5,744
Dividends paid	(31,794)	(30,773)
Excess tax benefit on stock-based compensation	26	1,248
Net cash used in continuing operations	(39,977)	(124,411)
Net cash provided by discontinued operations	0	0
Net cash used in financing activities	(39,977)	(124,411)
Effect of exchange rate changes on cash and cash equivalents	43	45
Decrease in cash and cash equivalents	(71,383)	(86,058)
Cash and cash equivalents - beginning of year	162,772	222,074
Cash and cash equivalents - end of year	$ 91,389	$ 136,016