Note 7 - Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019
Goodwill, Impairment Loss	$ 39,430		$ 0	$ 40,688	[1],[2]	$ 0
Impairment of Intangible Assets, Finite-lived	0		0	957		0
Amortization of Intangible Assets, Total	3,400		$ 3,400	10,200		$ 10,300
Finite-Lived Intangible Asset, Expected Amortization, Remainder of Fiscal Year	13,000			13,000
Finite-Lived Intangible Asset, Expected Amortization, Year One	12,900			12,900
Finite-Lived Intangible Asset, Expected Amortization, Year Two	12,900			12,900
Finite-Lived Intangible Asset, Expected Amortization, Year Three	12,900			12,900
Finite-Lived Intangible Asset, Expected Amortization, Year Four	12,100			12,100
Energy Services [Member]
Goodwill, Impairment Loss	$ 39,400	$ 1,300		40,688	[1],[2]
Impairment of Intangible Assets, Finite-lived				$ 1,000
Energy Services [Member] | Trademarks [Member]
Impairment of Intangible Assets, Finite-lived		300
Energy Services [Member] | Customer Relationships [Member]
Impairment of Intangible Assets, Finite-lived		$ 700

[1] During the second quarter of 2020, the Company recorded a $1.3 million goodwill impairment related to restructuring activities within Energy Services (see Note 4).

[2] During the third quarter of 2020, the Company recorded a $39.4 million goodwill impairment within Energy Services (see Note 2).