UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income (loss)	$ (16,905)	$ 3,306
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	142,295	136,129
Goodwill impairment charge	0	31,992
Allowance for doubtful accounts	3,228	4,536
Amortization of deferred financing costs and debt discount	1,772	1,639
Accretion of environmental liabilities	5,053	5,218
Changes in environmental liability estimates	(315)	887
Deferred income taxes	(6,521)	(908)
Stock-based compensation	4,739	6,146
Excess tax benefit of stock-based compensation	(2)	(102)
Net tax deficiency on stock based awards	(603)	(72)
Other expense	1,049	251
Environmental expenditures	(6,454)	(11,532)
Changes in assets and liabilities, net of acquisitions
Accounts receivable and unbilled accounts receivable	993	(133,031)
Inventories and supplies	(1,113)	17,694
Other current assets	(4,789)	(816)
Accounts payable	(8,397)	108,639
Other current and long-term liabilities	6,021	23,839
Net cash from operating activities	120,051	193,815
Cash flows used in investing activities:
Additions to property, plant and equipment	(123,529)	(124,145)
Proceeds from sales of fixed assets	2,668	2,646
Acquisitions, net of cash acquired	(58,989)	(79,610)
Additions to intangible assets, including costs to obtain or renew permits	(973)	(3,088)
Purchases of available-for-sale securities	(598)	0
Net cash used in investing activities	(181,421)	(204,197)
Cash flows from (used in) financing activities:
Change in uncashed checks	(11,022)	(22,160)
Proceeds from exercise of stock options	184	397
Issuance of restricted shares, net of shares remitted	(1,879)	(1,837)
Repurchases of common stock	(10,134)	(32,203)
Deferred financing costs paid	(2,614)	0
Payments on capital leases	0	(471)
Excess tax benefit of stock-based compensation	2	102
Issuance of senior secured notes, including premium	250,625	0
Net cash from (used in) financing activities	225,162	(56,172)
Effect of exchange rate change on cash	4,423	(6,704)
Increase (decrease) in cash and cash equivalents	168,215	(73,258)
Cash and cash equivalents, beginning of period	184,708	246,879
Cash and cash equivalents, end of period	352,923	173,621
Cash payments for interest and income taxes:
Interest paid	44,275	37,411
Income taxes paid	23,872	3,068
Non-cash investing and financing activities:
Property, plant and equipment accrued	24,187	34,799
Receivable for estimated purchase price adjustment	$ 0	$ 2,518