Note 8 - Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended	9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Goodwill, Period Increase (Decrease), Total	[1]				$ 1,900
Goodwill, Impairment Loss				$ 0
Amortization of Intangible Assets, Total		$ 41,500	$ 33,300		123,600	$ 100,100
Energy and Specialized Markets [Member]
Goodwill, Period Increase (Decrease), Total	[1]				$ (19,500)

[1] Of which $19.5 million relates to a segment reclassification, refer to Note 13. Segment Reporting