Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010
Cash flow from operating activities:
Net income	$ 45,463		$ 39,372
Adjustments to reconcile from net income (loss) to net cash provided by (used in) operating activities:
Depreciation, depletion, and amortization	30,945		26,470
Other non-cash charges	4,044		3,174
Changes in assets and liabilities, net of effects of acquisitions:
Decrease (increase) in current assets	(89,320)		(69,385)
Decrease (increase) in noncurrent assets	1,789		(2,298)
Increase (decrease) in current liabilities	24,894		34,832
Increase (decrease) in noncurrent liabilities	(1,170)		2,999
Net cash provided by (used in) operating activities	16,645		35,164
Cash flow from investing activities:
Capital expenditures	(43,824)		(37,944)
Investments in and advances to affiliates and joint ventures	(1,237)		(2,047)
Proceeds from sale of joint ventures	2,023
Other	2,118		1,210
Net cash (used in) investing activities	(40,920)		(38,781)
Cash flow from financing activities:
Net change in outstanding debt	14,891		21,004
Purchase of noncontrolling interest			(11,873)
Proceeds from sales of treasury stock	7,000		3,252
Dividends	(17,051)		(16,745)
Excess tax benefits from stock-based compensation	669		394
Net cash provided by (used in) financing activities	5,509		(3,968)
Effect of foreign currency rate changes on cash	849		242
Net increase (decrease) in cash and cash equivalents	(17,917)		(7,343)
Cash and cash equivalents at beginning of period	27,262	[1]	27,669
Cash and cash equivalents at end of period	$ 9,345		$ 20,326

[1] Condensed from audited financial statements.