Note 4 - Inventories (Details Textual) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accrued Inventory Payable	$ 1.1	$ 1.3

It represents the value of accrued inventory payable.

No definition available.

Name:	cui_AccruedInventoryPayable
Namespace Prefix:	cui_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant