UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities:
Net loss	$ (21,393)	$ (20,871)
Adjustments to reconcile net loss to net cash from operating activities:
Depreciation and amortization	72,412	68,902
Allowance for doubtful accounts	1,935	1,072
Amortization of deferred financing costs and debt discount	829	872
Accretion of environmental liabilities	2,290	2,505
Changes in environmental liability estimates	102	(95)
Deferred income taxes	196	7
Stock-based compensation	2,271	2,093
Net tax deficiency on stock based awards	0	(345)
Other expense	1,549	350
Environmental expenditures	(2,938)	(3,518)
Changes in assets and liabilities, net of acquisitions
Accounts receivable and unbilled accounts receivable	24,301	35,839
Inventories and supplies	(2,676)	(2,882)
Other current assets	(1,277)	1,838
Accounts payable	(13,609)	(36,195)
Other current and long-term liabilities	(6,873)	(10,283)
Net cash from operating activities	57,119	39,289
Cash flows used in investing activities:
Additions to property, plant and equipment	(42,462)	(75,781)
Proceeds from sales of fixed assets	1,030	1,273
Acquisitions, net of cash acquired	(11,946)	(34,993)
Proceeds on sale of business	2,018	0
Additions to intangible assets, including costs to obtain or renew permits	(751)	(512)
Proceeds from sale of investments	243	0
Net cash used in investing activities	(51,868)	(110,013)
Cash flows (used in) from financing activities:
Change in uncashed checks	(7,557)	(5,218)
Proceeds from exercise of stock options	46	0
Issuance of restricted shares, net of shares remitted	(1,021)	(1,425)
Repurchases of common stock	(6,796)	(4,998)
Deferred financing costs paid	(108)	(2,190)
Issuance of senior secured notes, including premium	0	250,625
Net cash (used in) from financing activities	(15,436)	236,794
Effect of exchange rate change on cash	554	4,567
(Decrease) increase in cash and cash equivalents	(9,631)	170,637
Cash and cash equivalents, beginning of period	306,997	184,708
Cash and cash equivalents, end of period	297,366	355,345
Cash payments for interest and income taxes:
Interest paid	21,717	21,808
Income taxes paid	5,519	5,848
Non-cash investing and financing activities:
Property, plant and equipment accrued	19,270	14,947
Receivable for estimated purchase price adjustment	$ 1,972	$ 250