Note 5 - Fair Value Measurements - Reconciliation of Contingent Consideration (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020
Beginning balance, January 1, 2021		$ 5,888
Payments		(3,750)	$ (4,000)
Ending balance, September 30, 2021		70,206
Contingent Consideration Liability [Member]
Beginning balance, January 1, 2021		5,888
Purchase price contingent consideration (1)	[1]	68,013
Changes in fair value		55
Payments		(3,750)
Ending balance, September 30, 2021		$ 70,206

[1] The increase in the contingent consideration liability is due to the contingent consideration associated with the acquisitions of Chilicon and Off Grid Energy. Refer to Note 2 for further information.