Note 20 - Other Equity Transactions (Details Textual) $ in Thousands	6 Months Ended
Jun. 30, 2018 USD ($)
Stock Compensation Expense Related to Royalties and Stock Bonuses Accrued But Not Issued	$ 18

Represents the amount of stock compensation during the period related to royalties and a stock bonus, which were earned and included in equity but not issued and outstanding at the end of the period.

No definition available.

Name:	cui_StockCompensationExpenseRelatedToRoyaltiesAndStockBonusesAccruedButNotIssued
Namespace Prefix:	cui_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration