UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ 43,534	$ (55,705)
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	205,189	205,480
Goodwill impairment charge	31,992	123,414
Allowance for doubtful accounts	5,631	6,743
Amortization of deferred financing costs and debt discount	2,459	2,457
Accretion of environmental liabilities	7,795	7,975
Changes in environmental liability estimates	(2,200)	(2,991)
Deferred income taxes	(18,994)	8,506
Stock-based compensation	6,550	6,446
Excess tax benefit of stock-based compensation	(102)	(829)
Deferred Tax Expense from Stock Options Exercised	(78)	829
Net tax (deficiency) benefit on stock based awards	(1,800)	(1,500)
Other expense (income)	390	(4,136)
Environmental expenditures	(16,773)	(12,130)
Changes in assets and liabilities, net of acquisitions
Accounts receivable and unbilled accounts receivable	(63,222)	(35,708)
Inventories and supplies	14,708	(20,675)
Other current assets	18,706	(10,048)
Accounts payable	47,051	(53,352)
Other current and long-term liabilities	26,957	29,763
Net cash from operating activities	309,593	196,039
Cash flows from investing activities:
Additions to property, plant and equipment	(189,999)	(198,877)
Proceeds from sales of fixed assets	3,740	5,913
Proceeds from sales of marketable securities	0	12,947
Acquisitions, net of cash acquired	(79,610)	(6,150)
Additions to intangible assets, including costs to obtain or renew permits	(4,633)	(5,443)
Other	0	914
Net cash used in investing activities	(270,502)	(190,696)
Cash flows from financing activities:
Change in uncashed checks	(21,882)	(591)
Proceeds from exercise of stock options	397	0
Issuance of restricted shares, net of shares remitted	(2,027)	(2,668)
Repurchases of common stock	(69,155)	(48,329)
Proceeds from employee stock purchase plan	0	4,364
Repayment of long-term obligations	0	5,000
Payments on capital leases	(500)	(1,682)
Excess tax benefit of stock-based compensation	102	829
Net cash from financing activities	(93,065)	(53,077)
Effect of exchange rate change on cash	(13,714)	(4,318)
Decrease in cash and cash equivalents	(67,688)	(52,052)
Cash and cash equivalents, beginning of period	246,879	310,073
Cash and cash equivalents, end of period	179,191	258,021
Cash payments for interest and income taxes:
Interest paid	58,613	58,446
Income taxes paid	32,276	21,737
Non-cash investing and financing activities:
Accrual for repurchased shares	658	5,464
Property, plant and equipment accrued	29,549	23,976
Receivable for estimated purchase price adjustment	$ 2,518	$ 0