Note 4 - Restructuring Charges (Details Textual) $ in Millions	3 Months Ended
Apr. 01, 2023 USD ($)
MCT Integration Program [Member]
Restructuring Expenses	$ 0.9

The amount of expenses associated with restructuring.

No definition available.

Name:	cohu_RestructuringExpenses
Namespace Prefix:	cohu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration