Note 2 - Acquisitions (Details Textual) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended		13 Months Ended
	Dec. 03, 2019	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020
EOS Power Panama Inc. [Member] | Forecast [Member]
Business Combination, Consideration Transferred, Total		$ 7,000
Majority Products Business of CUI Power [Member]
Business Combination, Consideration Transferred, Total	$ 32,000				$ 29,196
Payments to Acquire Businesses, Gross	32,000				$ 29,196
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual			$ 43,100	$ 2,200
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual			6,800	400
Business Combination, Acquisition Related Costs			200	$ 200
Majority Products Business of CUI Power [Member] | Trade Names [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	5,000
Majority Products Business of CUI Power [Member] | Customer Relationships [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 11,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life (Year)	13 years
EOS Power Panama Inc. [Member]
Revenues, Total			$ 12,000