Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ (19,448)	$ 3,087		$ (66,582)
Adjustments to reconcile to net cash provided by operating activities:
Depreciation and amortization	36,163	37,855		44,419
(Gain) loss on sale of fixed assets	(662)	143		(59)
Equity-based compensation expense	7,751	7,838		10,060
Deferred income taxes	3,146	(648)		(9,376)
Non-cash restructuring charges	12,782	13,814		10,080
Goodwill impairment	0	1,389	[1]	45,390
Definite-lived intangible asset impairment	0	2,169		41,032
Impairment of assets held for sale	23,427	0		0
Loss on sale of business	0	7,048		0
Loss on foreign currency transactions	503	623		2,152
Other	(744)	1,278		(1,562)
Changes in operating assets and liabilities (net of acquisitions):
Receivables net, retainage and contract assets	16,416	(6,821)		(29,847)
Inventories	(3,413)	2,306		(1,926)
Prepaid expenses and other assets	4,578	614		8,732
Accounts payable and accrued expenses	(6,711)	(7,339)		18,803
Contract liabilities	5,091	(24,144)		(5,924)
Other operating	(65)	457		(1,798)
Net cash provided by operating activities	78,814	39,669		63,594
Cash flows from investing activities:
Capital expenditures	(28,772)	(30,514)		(30,830)
Proceeds from sale of fixed assets	1,339	3,036		707
Patent expenditures	(293)	(299)		(379)
Other acquisition activity	0	(9,000)		(9,045)
Sale of Bayou, net of cash disposed	0	37,942		0
Net cash provided by (used in) investing activities	(27,726)	1,165		(39,547)
Cash flows from financing activities:
Proceeds from issuance of common stock upon stock option exercises	956	0		823
Repurchase of common stock	(30,393)	(25,775)		(37,849)
Investments from non-controlling interest	0	0		158
Distributions to non-controlling interests	(1,609)	0		(71)
Payment of contingent consideration	0	0		(500)
Credit facility amendment fees	0	(1,657)		0
Proceeds from (payments on) notes payable, net	(273)	234		639
Proceeds from (payments on) line of credit, net	(7,000)	(7,000)		2,000
Principal payments on long-term debt	(28,438)	(26,250)		(21,647)
Net cash used in financing activities	(66,757)	(60,448)		(56,447)
Effect of exchange rate changes on cash	(2,995)	(4,045)		6,553
Net decrease in cash, cash equivalents and restricted cash for the year	(18,664)	(23,659)		(25,847)
Cash, cash equivalents and restricted cash, beginning of year	84,886	108,545		134,392
Cash, cash equivalents and restricted cash, end of year	66,222	84,886		108,545
Cash, cash equivalents and restricted cash, assets held for sale, end of year	0	0		(989)
Cash, cash equivalents and restricted cash, end of year	66,222	84,886		107,556
Supplemental disclosures of cash flow information:
Interest	14,977	15,622		14,998
Income taxes	$ (1,579)	$ 4,625		$ 5,649

[1] During 2018, the Company recorded goodwill of $2.7 million and $1.3 million related to the acquisitions of Hebna and P2S, respectively (see Note 1).