UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net (loss) income	$ (27,160)	$ 43,534
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	215,655	205,189
Goodwill impairment charge	34,013	31,992
Allowance for doubtful accounts	6,203	5,631
Amortization of deferred financing costs and debt discount	2,685	2,459
Accretion of environmental liabilities	7,529	7,795
Changes in environmental liability estimates	(349)	(2,200)
Deferred income taxes	(28,826)	(18,994)
Stock-based compensation	7,735	6,550
Excess tax benefit of stock-based compensation	(21)	(102)
Net tax deficiency on stock based awards	(642)	(78)
Other expense	1,247	390
Gain on sale of business	(16,431)	0
Environmental expenditures	(9,374)	(16,773)
Changes in assets and liabilities, net of acquisitions
Accounts receivable and unbilled accounts receivable	(32,944)	(63,222)
Inventories and supplies	(13,722)	14,708
Other current assets	5,619	18,706
Accounts payable	(11,951)	47,051
Other current and long-term liabilities	39,561	26,957
Net cash from operating activities	178,827	309,593
Cash flows used in investing activities:
Additions to property, plant and equipment	(175,348)	(189,999)
Proceeds from sales of fixed assets	3,982	3,740
Acquisitions, net of cash acquired	(207,089)	(79,610)
Proceeds on sale of business, net of cash	47,134	0
Additions to intangible assets, including costs to obtain or renew permits	(1,920)	(4,633)
Purchases of available-for-sale securities	(598)	0
Net cash used in investing activities	(333,839)	(270,502)
Cash flows from (used in) financing activities:
Change in uncashed checks	(7,084)	(21,882)
Proceeds from exercise of stock options	230	397
Issuance of restricted shares, net of shares remitted	(2,500)	(2,027)
Repurchases of common stock	(15,869)	(69,155)
Deferred financing costs paid	(2,614)	0
Payments on capital leases	0	(500)
Excess tax benefit of stock-based compensation	21	102
Issuance of senior secured notes, including premium	250,625	0
Net cash from (used in) financing activities	222,809	(93,065)
Effect of exchange rate change on cash	5,352	(13,714)
Increase (decrease) in cash and cash equivalents	73,149	(67,688)
Cash and cash equivalents, beginning of period	184,708	246,879
Cash and cash equivalents, end of period	257,857	179,191
Cash payments for interest and income taxes:
Interest paid	66,261	58,613
Income taxes paid	27,196	32,276
Non-cash investing and financing activities:
Accrual for repurchased shares	479	658
Property, plant and equipment accrued	18,181	29,549
Receivable for estimated purchase price adjustment	$ 1,910	$ 2,518