Note 3 - Revenues (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

Disaggregation of Revenue [Table Text Block]

	Quarter Ended June 30, 2019								Quarter Ended June 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Geographic region:
United States	$	110,957	$	43,326	$	85,704	$	239,987	$	117,580	$	58,210	$	77,909	$	253,699
Canada		18,934		14,458		—		33,392		15,607		14,819		—		30,426
Europe		12,888		4,493		—		17,381		12,996		2,850		—		15,846
Other foreign		12,661		15,319		—		27,980		14,549		20,510		—		35,059
Total revenues	$	155,440	$	77,596	$	85,704	$	318,740	$	160,732	$	96,389	$	77,909	$	335,030

	Six Months Ended June 30, 2019								Six Months Ended June 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Geographic region:
United States	$	208,848	$	73,347	$	166,567	$	448,762	$	211,425	$	108,568	$	170,238	$	490,231
Canada		29,545		27,915		—		57,460		27,876		31,389		—		59,265
Europe		25,413		7,971		—		33,384		26,140		5,715		—		31,855
Other foreign		23,177		32,861		—		56,038		29,718		48,822		—		78,540
Total revenues	$	286,983	$	142,094	$	166,567	$	595,644	$	295,159	$	194,494	$	170,238	$	659,891

	Quarter Ended June 30, 2019								Quarter Ended June 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Contract type:
Fixed fee	$	136,212	$	53,055	$	1,291	$	190,558	$	149,532	$	63,982	$	5,967	$	219,481
Time and materials		—		17,283		84,413		101,696		—		21,441		71,942		93,383
Product sales		19,184		7,258		—		26,442		11,187		10,966		—		22,153
License fees		44		—		—		44		13		—		—		13
Total revenues	$	155,440	$	77,596	$	85,704	$	318,740	$	160,732	$	96,389	$	77,909	$	335,030

	Six Months Ended June 30, 2019								Six Months Ended June 30, 2018
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Contract type:
Fixed fee	$	255,127	$	95,628	$	2,210	$	352,965	$	274,794	$	141,883	$	11,724	$	428,401
Time and materials		—		32,259		164,357		196,616		—		34,549		158,514		193,063
Product sales		31,662		14,207		—		45,869		20,332		18,062		—		38,394
License fees		194		—		—		194		33		—		—		33
Total revenues	$	286,983	$	142,094	$	166,567	$	595,644	$	295,159	$	194,494	$	170,238	$	659,891

Contract Asset and Liability [Table Text Block]

	June 30, 2019(1)			December 31, 2018(2)
Contract assets – current	$	56,661		$	62,467
Contract liabilities – current		(25,387	)		(32,339	)
Net contract assets	$	31,274		$	30,128