CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net income	$ 89,019	$ 107,186
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	87,000	67,671
Allowance for doubtful accounts	623	163
Amortization of deferred financing costs and debt discount	1,230	2,221
Accretion of environmental liabilities	7,231	7,799
Changes in environmental liability estimates	(2,467)	(5,391)
Deferred income taxes	(197)	540
Stock-based compensation	5,329	5,220
Excess tax benefit of stock-based compensation	(1,949)	(1,221)
Income tax benefit related to stock option exercises	1,949	1,215
Gains on sales of businesses	0	(2,678)
Other income	(2,577)	(2,485)
Write-off deferred financing costs and debt discount	0	1,394
Environmental expenditures	(8,551)	(8,704)
Changes in assets and liabilities, net of acquisitions
Accounts receivable	(32,670)	(63,714)
Other current assets	(14,113)	(18,456)
Accounts payable	30,241	47,828
Other current liabilities	(8,762)	15,342
Net cash from operating activities	151,336	153,930
Cash flows from investing activities:
Additions to property, plant and equipment	(113,644)	(74,741)
Acquisitions, net of cash acquired	(336,960)	(13,846)
Additions to intangible assets, including costs to obtain or renew permits	(2,356)	(3,262)
Purchase of available for sale securities	0	(1,486)
Proceeds from sales of marketable securities	425	2,627
Proceeds from sales of fixed assets and assets held for sale	5,925	15,963
Proceeds from insurance settlement	0	1,336
Proceeds from sale of long-term investments	1,000	1,300
Net cash used in investing activities	(445,610)	(72,109)
Cash flows from financing activities:
Change in uncashed checks	(2,580)	(4,682)
Proceeds from exercise of stock options	1,089	550
Remittance of shares, net	(1,897)	(198)
Proceeds from employee stock purchase plan	2,451	1,769
Deferred financing costs paid	(8,442)	(53)
Payments on capital leases	(5,775)	(3,361)
Distribution of cash earned on employee participation plan	(189)	(148)
Excess tax benefit of stock-based compensation	1,949	1,221
Principal payment on debt	0	(30,000)
Issuance of senior secured notes, including premium	261,250	0
Net cash from financing activities	247,856	(34,902)
Effect of exchange rate change on cash	1,367	451
(Decrease) increase in cash and cash equivalents	(45,051)	47,370
Cash and cash equivalents, beginning of period	302,210	233,546
Cash and cash equivalents, end of period	257,159	280,916
Cash payments for interest and income taxes:
Interest paid	30,169	26,230
Income taxes paid	35,085	39,813
Non-cash investing and financing activities:
Property, plant and equipment accrued	20,288	4,775
Assets acquired through capital lease	1,471	10,130
Issuance of acquisition-related common stock, net	$ 0	$ 1,015