CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net income	$ 51,886	$ 68,359
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	52,396	44,779
Allowance for doubtful accounts	402	833
Amortization of deferred financing costs and debt discount	898	1,475
Accretion of environmental liabilities	4,796	5,304
Changes in environmental liability estimates	(773)	(3,893)
Deferred income taxes	819	388
Stock-based compensation	2,880	3,107
Excess tax benefit of stock-based compensation	(1,617)	(782)
Income tax benefit related to stock option exercises	1,617	777
Gains on sales of businesses		(2,678)
Other income	(2,413)	(3,154)
Environmental expenditures	(5,564)	(4,717)
Changes in assets and liabilities, net of acquisitions
Accounts receivable	18,063	(61,294)
Other current assets	(5,252)	(20,868)
Accounts payable	(33,024)	48,411
Other current liabilities	(9,485)	21,270
Net cash from operating activities	75,629	97,317
Cash flows from investing activities:
Additions to property, plant and equipment	(65,460)	(35,490)
Acquisitions, net of cash acquired	(205,922)	(13,751)
Additions to intangible assets, including costs to obtain or renew permits	(1,066)	(2,192)
Proceeds from sales of marketable securities	388	2,575
Proceeds from sales of fixed assets and assets held for sale	4,891	15,594
Proceeds from insurance settlement		1,336
Proceeds from sale of long-term investments		1,300
Net cash used in investing activities	(267,169)	(30,628)
Cash flows from financing activities:
Change in uncashed checks	13,746	(3,600)
Proceeds from exercise of stock options	783	318
Remittance of shares, net	(1,807)	(113)
Proceeds from employee stock purchase plan	1,556	1,187
Deferred financing costs paid	(8,099)	(53)
Payments on capital leases	(3,316)	(1,752)
Distribution of cash earned on employee participation plan	(189)	(148)
Excess tax benefit of stock-based compensation	1,617	782
Issuance of senior secured notes, including premium	261,250
Net cash from financing activities	265,541	(3,379)
Effect of exchange rate change on cash	1,365	(1,556)
Increase in cash and cash equivalents	75,366	61,754
Cash and cash equivalents, beginning of period	302,210	233,546
Cash and cash equivalents, end of period	377,576	295,300
Cash payments for interest and income taxes:
Interest paid	11,551	13,572
Income taxes paid	26,545	10,845
Non-cash investing and financing activities:
Property, plant and equipment accrued	24,586	4,738
Assets acquired through capital lease		9,418
Issuance of acquisition-related common stock, net		$ 1,015