Note 7 - Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2020	Dec. 31, 2019
Gross carrying amount		$ 217,788	$ 219,623
Accumulated amortization		(120,645)	(114,795)
Net carrying amount		$ 97,143	104,828
Licensing Agreements [Member]
Weighted average useful lives (Year)		2 months 12 days
Gross carrying amount		$ 3,894	3,894
Accumulated amortization		(3,871)	(3,824)
Net carrying amount		$ 23	70
Lease Agreements [Member]
Weighted average useful lives (Year)		6 months
Gross carrying amount		$ 864	864
Accumulated amortization		(820)	(777)
Net carrying amount		$ 44	87
Trademarks [Member]
Weighted average useful lives (Year)	[1]	9 years 2 months 12 days
Gross carrying amount	[1]	$ 15,437	15,699
Accumulated amortization	[1]	(7,261)	(6,911)
Net carrying amount	[1]	$ 8,176	8,788
Noncompete Agreements [Member]
Weighted average useful lives (Year)		2 years 10 months 24 days
Gross carrying amount		$ 2,048	2,301
Accumulated amortization		(1,391)	(1,354)
Net carrying amount		$ 657	947
Customer Relationships [Member]
Weighted average useful lives (Year)	[1]	6 years 10 months 24 days
Gross carrying amount	[1]	$ 156,817	157,576
Accumulated amortization	[1]	(81,931)	(76,832)
Net carrying amount	[1]	$ 74,886	80,744
Patents [Member]
Weighted average useful lives (Year)		7 years 3 months 18 days
Gross carrying amount		$ 38,728	39,289
Accumulated amortization		(25,371)	(25,097)
Net carrying amount		$ 13,357	$ 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).