Note 7 - Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2020	Dec. 31, 2019
Gross carrying amount		$ 218,339	$ 219,623
Accumulated amortization		(124,394)	(114,795)
Net carrying amount		$ 93,945	104,828
Licensing Agreements [Member]
Weighted average useful lives (Year)		0 years
Gross carrying amount		$ 3,894	3,894
Accumulated amortization		(3,894)	(3,824)
Net carrying amount		$ (0)	70
Lease Agreements [Member]
Weighted average useful lives (Year)		3 months 18 days
Gross carrying amount		$ 864	864
Accumulated amortization		(842)	(777)
Net carrying amount		$ 22	87
Trademarks [Member]
Weighted average useful lives (Year)	[1]	5 years 7 months 6 days
Gross carrying amount	[1]	$ 15,466	15,699
Accumulated amortization	[1]	(7,462)	(6,911)
Net carrying amount	[1]	$ 8,004	8,788
Noncompete Agreements [Member]
Weighted average useful lives (Year)		6 months
Gross carrying amount		$ 2,051	2,301
Accumulated amortization		(1,448)	(1,354)
Net carrying amount		$ 604	947
Customer Relationships [Member]
Weighted average useful lives (Year)	[1]	6 years 3 months 18 days
Gross carrying amount	[1]	$ 156,897	157,576
Accumulated amortization	[1]	(84,574)	(76,832)
Net carrying amount	[1]	$ 72,323	80,744
Patents [Member]
Weighted average useful lives (Year)		5 years 10 months 24 days
Gross carrying amount		$ 39,167	39,289
Accumulated amortization		(26,174)	(25,097)
Net carrying amount		$ 12,993	$ 14,192

[1] During the second quarter of 2020, the Company recorded intangible asset impairments related to restructuring activities within Energy Services of $0.3 million for trademarks and $0.7 million for customer relationships (see Note 4).