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Revenue - Disaggregated Revenues by Segment (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 168,218	$ 178,462	$ 179,031	$ 161,662	$ 171,163	$ 174,556	$ 177,677	$ 153,735	$ 160,777	$ 147,894	$ 124,435	$ 159,465	$ 687,373	$ 677,131	$ 592,571
United States
Disaggregation of Revenue [Line Items]
Revenue													489,873	475,222	411,489
Other Americas
Disaggregation of Revenue [Line Items]
Revenue													89,254	83,643	72,835
Europe
Disaggregation of Revenue [Line Items]
Revenue													100,919	109,614	100,541
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													7,327	8,652	7,706
Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													387,752	366,920	319,483
Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													80,552	68,392	70,271
Industrials
Disaggregation of Revenue [Line Items]
Revenue													63,983	67,715	66,428
Power Generation and Transmission
Disaggregation of Revenue [Line Items]
Revenue													42,104	52,746	39,887
Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													54,827	51,399	34,871
Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													27,223	32,290	33,787
Petrochemical
Disaggregation of Revenue [Line Items]
Revenue													15,896	19,605	19,280
Other
Disaggregation of Revenue [Line Items]
Revenue													15,036	18,064	8,564
Operating segments | Services
Disaggregation of Revenue [Line Items]
Revenue													573,336	555,387	476,164
Operating segments | Services | United States
Disaggregation of Revenue [Line Items]
Revenue													485,551	472,125	406,437
Operating segments | Services | Other Americas
Disaggregation of Revenue [Line Items]
Revenue													83,877	80,013	68,150
Operating segments | Services | Europe
Disaggregation of Revenue [Line Items]
Revenue													2,811	1,841	904
Operating segments | Services | Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													1,097	1,408	673
Operating segments | Services | Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													356,763	330,880	279,723
Operating segments | Services | Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													61,475	51,593	50,813
Operating segments | Services | Industrials
Disaggregation of Revenue [Line Items]
Revenue													38,197	41,873	44,919
Operating segments | Services | Power Generation and Transmission
Disaggregation of Revenue [Line Items]
Revenue													31,197	39,966	30,005
Operating segments | Services | Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													40,778	38,742	24,671
Operating segments | Services | Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													15,283	16,809	17,070
Operating segments | Services | Petrochemical
Disaggregation of Revenue [Line Items]
Revenue													15,360	19,378	18,882
Operating segments | Services | Other
Disaggregation of Revenue [Line Items]
Revenue													14,283	16,146	10,081
Operating segments | International
Disaggregation of Revenue [Line Items]
Revenue													112,425	117,245	107,556
Operating segments | International | United States
Disaggregation of Revenue [Line Items]
Revenue													910	912	911
Operating segments | International | Other Americas
Disaggregation of Revenue [Line Items]
Revenue													9,076	5,003	4,581
Operating segments | International | Europe
Disaggregation of Revenue [Line Items]
Revenue													99,714	108,411	99,953
Operating segments | International | Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													2,725	2,919	2,111
Operating segments | International | Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													30,654	35,232	39,383
Operating segments | International | Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													18,763	16,513	18,166
Operating segments | International | Industrials
Disaggregation of Revenue [Line Items]
Revenue													23,703	24,000	19,657
Operating segments | International | Power Generation and Transmission
Disaggregation of Revenue [Line Items]
Revenue													8,304	9,927	7,559
Operating segments | International | Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													14,021	12,593	10,029
Operating segments | International | Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													7,946	11,496	10,353
Operating segments | International | Petrochemical
Disaggregation of Revenue [Line Items]
Revenue													536	227	345
Operating segments | International | Other
Disaggregation of Revenue [Line Items]
Revenue													8,498	7,257	2,064
Operating segments | Products
Disaggregation of Revenue [Line Items]
Revenue													12,727	13,831	16,449
Operating segments | Products | United States
Disaggregation of Revenue [Line Items]
Revenue													6,495	6,469	7,551
Operating segments | Products | Other Americas
Disaggregation of Revenue [Line Items]
Revenue													406	395	550
Operating segments | Products | Europe
Disaggregation of Revenue [Line Items]
Revenue													1,896	2,174	3,154
Operating segments | Products | Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													3,930	4,793	5,194
Operating segments | Products | Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													335	808	377
Operating segments | Products | Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													314	286	1,292
Operating segments | Products | Industrials
Disaggregation of Revenue [Line Items]
Revenue													2,083	1,842	1,852
Operating segments | Products | Power Generation and Transmission
Disaggregation of Revenue [Line Items]
Revenue													2,603	2,853	2,323
Operating segments | Products | Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													28	64	171
Operating segments | Products | Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													3,994	3,985	6,364
Operating segments | Products | Petrochemical
Disaggregation of Revenue [Line Items]
Revenue													0	0	53
Operating segments | Products | Other
Disaggregation of Revenue [Line Items]
Revenue													3,370	3,993	4,017
Corp/Elim
Disaggregation of Revenue [Line Items]
Revenue													(11,115)	(9,332)	(7,598)
Corp/Elim | United States
Disaggregation of Revenue [Line Items]
Revenue													(3,083)	(4,284)	(3,410)
Corp/Elim | Other Americas
Disaggregation of Revenue [Line Items]
Revenue													(4,105)	(1,768)	(446)
Corp/Elim | Europe
Disaggregation of Revenue [Line Items]
Revenue													(3,502)	(2,812)	(3,470)
Corp/Elim | Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenue													(425)	(468)	(272)
Corp/Elim | Oil & Gas
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim | Aerospace & Defense
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim | Industrials
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim | Power Generation and Transmission
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim | Other Process Industries
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim | Infrastructure, Research & Engineering
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim | Petrochemical
Disaggregation of Revenue [Line Items]
Revenue													0	0	0
Corp/Elim | Other
Disaggregation of Revenue [Line Items]
Revenue													$ (11,115)	$ (9,332)	$ (7,598)

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