Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ 19,931	$ (756)
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	23,964	23,155
Gain on sale of fixed assets	(223)	(1,225)
Equity-based compensation expense	6,736	5,616
Deferred income taxes	5,353	(1,054)
Non-cash restructuring charges	102	276
Loss on foreign currency transactions	862	1,638
Other	(1,150)	889
Changes in operating assets and liabilities (net of acquisitions):
Restricted cash related to operating activities	1,346	1,693
Receivables net, retainage and costs and estimated earnings in excess of billings	(36,862)	16,027
Inventories	(4,855)	(311)
Prepaid expenses and other assets	19,062	(4,056)
Accounts payable and accrued expenses	(3,210)	(37,908)
Billings in excess of costs and estimated earnings	(30,503)	5,409
Other operating	310	512
Net cash provided by operating activities	863	9,905
Cash flows from investing activities:
Capital expenditures	(12,829)	(19,445)
Proceeds from sale of fixed assets	430	2,426
Patent expenditures	(246)	(911)
Restricted cash related to investing activities	2,000	(1,086)
Purchase of Underground Solutions, Inc., net of cash acquired	0	(85,167)
Other acquisition activity, net of cash acquired	(9,045)	(6,035)
Sale of interest in Bayou Perma-Pipe Canada, Ltd., net of cash disposed	0	4,599
Net cash used in investing activities	(19,690)	(105,619)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises	0	13
Repurchase of common stock	(21,034)	(25,200)
Distributions to non-controlling interests	35	1,276
Payment of contingent consideration	500	500
Proceeds from line of credit, net	17,000	36,000
Principal payments on long-term debt	(8,750)	(8,750)
Net cash provided by (used in) financing activities	(13,319)	287
Effect of exchange rate changes on cash	7,977	(5,477)
Net decrease in cash and cash equivalents for the period	(24,169)	(100,904)
Cash and cash equivalents, beginning of period	129,500	211,696
Cash and cash equivalents, end of period	$ 105,331	$ 110,792