Note 2 - Summary of Significant Accounting Policies - Estimated Useful Life for the Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2017
Tradename - CUI [Member]
Indefinite-lived intangible assets (Year)		[1]
Customer List - CUI [Member]
Indefinite-lived intangible assets (Year)		[1]
Patent Pending Technology [Member]
Indefinite-lived intangible assets (Year)		[1]
Order or Production Backlog [Member]
Finite-lived intangible assets (Year)	2 years
Trade name - Orbital [Member]
Finite-lived intangible assets (Year)	10 years
Trade name - V-Infinity [Member]
Finite-lived intangible assets (Year)	5 years
Tradename - CUI-Canada [Member]
Finite-lived intangible assets (Year)	3 years
Customer List - Orbital [Member]
Finite-lived intangible assets (Year)	10 years
Customer List - CUI Canada [Member]
Finite-lived intangible assets (Year)	7 years
Developed Technology Rights [Member]
Finite-lived intangible assets (Year)	20 years	[2]
Technology - Based Asset - Know How [Member]
Finite-lived intangible assets (Year)	12 years
Technology -Based Asset - Software [Member]
Finite-lived intangible assets (Year)	10 years
Technology - Based Asset - Power [Member]
Finite-lived intangible assets (Year)	7 years
Computer Software, Intangible Asset [Member] | Minimum [Member]
Finite-lived intangible assets (Year)	3 years
Computer Software, Intangible Asset [Member] | Maximum [Member]
Finite-lived intangible assets (Year)	5 years	[3]
Patents [Member]
Finite-lived intangible assets (Year)		[4]
Other Intangible Assets [Member]
Finite-lived intangible assets (Year)		[5]

[1] Indefinite-lived intangible assets are reviewed annually for impairment and when circumstances suggest.

[2] Technology rights include $1.0 million of capitalized costs that are related to our CUI-Canada acquisition in March 2015. The CUI-Canada technology rights are amortized over a 7-year life. The rest of the technology rights are amortized over a 20-year life.

[3] Software assets are recorded at cost and include major expenditures, which increase productivity or substantially increase useful lives.

[4] Patents are amortized over the life of the patent. Any patents not approved will be expensed at that time.

[5] Other intangible assets are amortized over an appropriate useful life, as determined by management in relation to the other intangible asset characteristics.