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)	$ (756)	$ 10,220
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	23,155	21,097
Gain on sale of fixed assets	(1,225)	(970)
Equity-based compensation expense	5,616	4,582
Deferred income taxes	(1,054)	2,001
Non-cash restructuring charges	276	1,212
Loss on sale of businesses	0	2,864
Loss on foreign currency transactions	1,638	424
Other	889	(1,391)
Changes in operating assets and liabilities (net of acquisitions):
Restricted cash related to operating activities	1,693	(1,128)
Receivables net, retainage and costs and estimated earnings in excess of billings	16,027	(6,410)
Inventories	(311)	1,377
Prepaid expenses and other assets	(4,056)	(221)
Accounts payable and accrued expenses	(37,908)	3,702
Billings in excess of costs and estimated earnings	5,409	21,021
Other operating	512	49
Net cash provided by operating activities	9,905	58,429
Cash flows from investing activities:
Capital expenditures	(19,445)	(12,087)
Proceeds from sale of fixed assets	2,426	1,186
Patent expenditures	(911)	(1,576)
Restricted cash related to investing activities	(1,086)	0
Purchase of Underground Solutions, Inc., net of cash acquired	(85,167)	0
Purchase of Fyfe Europe S.A. and related companies	(2,800)	0
Purchase of CIPP business of Leif M. Jensen A/S	(3,235)	0
Purchase of Schultz Mechanical Contractors, Inc.	0	(6,878)
Sale of interest in Bayou Perma-Pipe Canada, Ltd., net of cash disposed	4,599	0
Payment to Fyfe Asia sellers for final net working capital	0	(5)
Net cash used in investing activities	(105,619)	(19,360)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises, including tax effects	13	1,299
Repurchase of common stock	(25,200)	(21,926)
Distributions to non-controlling interests	(1,276)	0
Payment of contingent consideration related to acquisition of Schultz Mechanical Contractors, Inc.	(500)	0
Proceeds on notes payable	0	1,505
Principal payments on notes payable	0	(1,875)
Proceeds from line of credit	37,000	26,000
Payments on line of credit	(1,000)	0
Principal payments on long-term debt	(8,750)	(39,593)
Net cash provided by (used in) financing activities	287	(34,590)
Effect of exchange rate changes on cash	(5,477)	(6,372)
Net decrease in cash and cash equivalents for the period	(100,904)	(1,893)
Cash and cash equivalents, beginning of period	209,253	174,965
Cash and cash equivalents, end of period	$ 110,792	$ 173,072