Note 3 - Revenues (Tables)

9 Months Ended

Sep. 30, 2019

Notes Tables

Disaggregation of Revenue [Table Text Block]

	Quarter Ended September 30, 2019								Quarter Ended September 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Geographic region:
United States	$	112,357	$	42,746	$	76,801	$	231,904	$	111,902	$	56,298	$	78,374	$	246,574
Canada		17,775		14,349		—		32,124		16,153		19,767		—		35,920
Europe		12,889		3,458		—		16,347		13,460		2,821		—		16,281
Other foreign		13,066		15,348		—		28,414		14,166		26,738		—		40,904
Total revenues	$	156,087	$	75,901	$	76,801	$	308,789	$	155,681	$	105,624	$	78,374	$	339,679

	Nine Months Ended September 30, 2019								Nine Months Ended September 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Geographic region:
United States	$	321,205	$	116,093	$	243,368	$	680,666	$	323,327	$	164,866	$	248,612	$	736,805
Canada		47,320		42,264		—		89,584		44,028		51,157		—		95,185
Europe		38,302		11,429		—		49,731		39,600		8,535		—		48,135
Other foreign		36,242		48,210		—		84,452		43,885		75,560		—		119,445
Total revenues	$	443,069	$	217,996	$	243,368	$	904,433	$	450,840	$	300,118	$	248,612	$	999,570

	Quarter Ended September 30, 2019								Quarter Ended September 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Contract type:
Fixed fee	$	139,363	$	53,704	$	1,003	$	194,070	$	141,598	$	68,935	$	2,069	$	212,602
Time and materials		—		16,092		75,798		91,890		—		25,612		76,305		101,917
Product sales		16,675		6,105		—		22,780		11,679		11,077		—		22,756
License fees		49		—		—		49		2,404		—		—		2,404
Total revenues	$	156,087	$	75,901	$	76,801	$	308,789	$	155,681	$	105,624	$	78,374	$	339,679

	Nine Months Ended September 30, 2019								Nine Months Ended September 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Contract type:
Fixed fee	$	394,489	$	149,333	$	3,213	$	547,035	$	416,392	$	210,819	$	13,793	$	641,004
Time and materials		—		48,351		240,155		288,506		—		60,160		234,819		294,979
Product sales		48,337		20,312		—		68,649		32,011		29,139		—		61,150
License fees		243		—		—		243		2,437		—		—		2,437
Total revenues	$	443,069	$	217,996	$	243,368	$	904,433	$	450,840	$	300,118	$	248,612	$	999,570

Contract Asset and Liability [Table Text Block]

	September 30, 2019 (1)			December 31, 2018 (2)
Contract assets – current	$	56,603		$	62,467
Contract liabilities – current		(30,635	)		(32,339	)
Net contract assets	$	25,968		$	30,128