Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ (53,851)	$ 11,031
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	34,410	34,406
Gain on sale of fixed assets	(6)	(1,960)
Equity-based compensation expense	9,206	7,689
Deferred income taxes	(4,511)	(613)
Non-cash restructuring charges	102	300
Goodwill impairment	45,390	0
Definite-lived intangible asset impairment	41,032	0
Loss on foreign currency transactions	1,659	1,351
Other	(1,129)	440
Changes in operating assets and liabilities (net of acquisitions):
Restricted cash related to operating activities	1,117	1,704
Receivables net, retainage and costs and estimated earnings in excess of billings	(54,040)	26,402
Inventories	(4,645)	(510)
Prepaid expenses and other assets	6,562	(3,094)
Accounts payable and accrued expenses	23,726	(41,698)
Billings in excess of costs and estimated earnings	(9,869)	212
Other operating	(79)	1,038
Net cash provided by operating activities	35,074	36,698
Cash flows from investing activities:
Capital expenditures	(22,515)	(31,485)
Proceeds from sale of fixed assets	423	3,083
Patent expenditures	(340)	(1,034)
Restricted cash related to investing activities	2,000	(1,086)
Purchase of Underground Solutions, Inc., net of cash acquired	0	(84,740)
Other acquisition activity, net of cash acquired	(9,045)	(11,567)
Sale of interest in Bayou Perma-Pipe Canada, Ltd., net of cash disposed	0	6,599
Net cash used in investing activities	(29,477)	(120,230)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises	0	37
Repurchase of common stock	(31,730)	(36,597)
Investments from non-controlling interests	158	0
Distributions to non-controlling interests	(71)	(1,276)
Payment of contingent consideration	(500)	(500)
Proceeds from notes payable	150	0
Proceeds from line of credit, net	14,000	36,000
Principal payments on long-term debt	(15,085)	(13,125)
Net cash used in financing activities	(33,078)	(15,461)
Effect of exchange rate changes on cash	1,677	561
Net decrease in cash and cash equivalents for the period	(25,804)	(98,432)
Cash and cash equivalents, beginning of year	129,500	211,696
Cash and cash equivalents, end of period	103,696	113,264
Cash and cash equivalents associated with assets held for sale, end of period	8,909	0
Cash and cash equivalents from continuing operations, end of period	$ 94,787	$ 113,264