Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ (3,949)	$ 1,372
Adjustments to reconcile to net cash used in operating activities:
Depreciation and amortization	11,376	10,486
Gain on sale of fixed assets	(499)	(200)
Equity-based compensation expense	2,363	1,663
Deferred income taxes	(1,187)	(969)
Non-cash restructuring charges	(212)	(1,359)
Loss on sale of businesses	0	2,864
Loss on foreign currency transactions	1,131	216
Other	(485)	(394)
Changes in operating assets and liabilities (net of acquisitions):
Restricted cash related to operating activities	462	(1,093)
Receivables net, retainage and costs and estimated earnings in excess of billings	29,618	(17,442)
Inventories	(1,806)	(3,455)
Prepaid expenses and other assets	3,382	2,379
Accounts payable and accrued expenses	(39,086)	(24,146)
Billings in excess of costs and estimated earnings	(3,672)	16,896
Other operating	582	981
Net cash used in operating activities	(1,982)	(12,201)
Cash flows from investing activities:
Capital expenditures	(10,060)	(4,234)
Proceeds from sale of fixed assets	956	297
Patent expenditures	(541)	(7)
Restricted cash related to investing activities	(1,086)	0
Purchase of Underground Solutions, Inc., net of cash acquired	(85,167)	0
Purchase of Schultz Mechanical Contractors, Inc.	(500)	(6,479)
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	(1,098)
Net cash used in investing activities	(91,799)	(11,521)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises, including tax effects	38	1,399
Repurchase of common stock	(16,325)	(7,622)
Proceeds on notes payable	0	1,505
Proceeds from line of credit	34,000	26,000
Principal payments on long-term debt	(4,375)	(33,031)
Net cash provided by (used in) financing activities	13,338	(11,749)
Effect of exchange rate changes on cash	(3,394)	(3,569)
Net decrease in cash and cash equivalents for the period	(83,837)	(39,040)
Cash and cash equivalents, beginning of period	209,253	174,965
Cash and cash equivalents, end of period	$ 127,859	$ 135,925