Note 8 - Overdraft Facility and Working Capital Line of Credit - Revolving Line of Credit (Details) £ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)		Dec. 31, 2018 GBP (£)
General Intangibles [Member] | CUI, Inc [Member]
CUI Inc. and CUI-Canada General intangibles, net	$ 8,546
Accounts Receivable [Member] | CUI, Inc [Member]
CUI Inc. and CUI-Canada General intangibles, net	9,102
Inventory [Member] | CUI, Inc [Member]
CUI Inc. and CUI-Canada General intangibles, net	11,403
Equipment [Member] | CUI, Inc [Member]
CUI Inc. and CUI-Canada General intangibles, net	1,438
Multi-currency Variable Rate Overdraft Facility [Member] | Wells Fargo Bank N.A [Member]
Line of credit facility, maximum borrowing capacity	52,021		£ 1,344
Multi-currency Variable Rate Overdraft Facility [Member] | Wells Fargo Bank [Member]
Line of credit facility, maximum borrowing capacity	5,000	[1]
Line of credit facility	$ 979	[2]
Line of credit facility, expiration date	Jun. 01, 2019
Line of credit facility, Fixed interest rate	2.25%		2.25%
Line of credit facility, variable interest rate	2.25%

[1] $2 million of the line of credit is reserved to guarantee the obligation of Orbital Gas Systems, Ltd. under its Overdraft Facility.

[2] As a result of the Company's cash management system, checks issued but not presented to the bank for payment may create negative book cash balances. When those checks are presented for payment if there isn't sufficient cash in the bank account, the checks would be honored by the bank with a corresponding increase to CUI Inc's draw on its line of credit. The balance shown above includes the effect of a $27 thousand negative book cash balance at CUI Inc. as of December 31, 2018.