Note 3 - Revenues (Tables)

3 Months Ended

Mar. 31, 2020

Notes Tables

Disaggregation of Revenue [Table Text Block]

	Quarter Ended March 31, 2020								Quarter Ended March 31, 2019
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Geographic region:
United States	$	103,418	$	38,739	$	91,063	$	233,220	$	97,891	$	30,021	$	80,863	$	208,775
Canada		11,023		10,832		—		21,855		10,611		13,457		—		24,068
Europe		7,642		3,029		—		10,671		12,525		3,478		—		16,003
Other foreign		8,161		13,468		—		21,629		10,516		17,542		—		28,058
Total revenues	$	130,244	$	66,068	$	91,063	$	287,375	$	131,543	$	64,498	$	80,863	$	276,904

	Quarter Ended March 31, 2020								Quarter Ended March 31, 2019
	Infrastructure Solutions		Corrosion Protection		Energy Services		Total		Infrastructure Solutions		Corrosion Protection		Energy Services		Total
Contract type:
Fixed fee	$	112,511	$	44,255	$	1,730	$	158,496	$	118,915	$	42,572	$	919	$	162,406
Time and materials		—		12,970		89,333		102,303		—		14,977		79,944		94,921
Product sales		17,733		8,843		—		26,576		12,478		6,949		—		19,427
License fees		—		—		—		—		150		—		—		150
Total revenues	$	130,244	$	66,068	$	91,063	$	287,375	$	131,543	$	64,498	$	80,863	$	276,904

Contract Asset and Liability [Table Text Block]

	March 31, 2020 (1)			December 31, 2019 (2)
Contract assets – current	$	55,978		$	51,092
Contract liabilities – current		(39,480	)		(37,562	)
Net contract assets	$	16,498		$	13,530