Stockholder Rights Plan - Additional Information (Detail)	1 Months Ended
	Nov. 30, 2006	Sep. 30, 1999	Nov. 30, 1996
Class of Stock [Line Items]
Dividends payable, date of record			Dec. 03, 1996
Effect of stock split	Each one-half of a Right entitles the holder to purchase one two-hundredth (1/200) of a share of Series A Preferred Stock for $95.	As a result of the two-for-one stock split in September, 1999, each share of common stock was associated with one-half of a Right entitling the holder to purchase one two-hundredth (1/200) of a share of Series A Preferred Stock for $45	Each Right entitled the holder to buy one one-hundredth (1/100) of a share of Cohu's Series A Preferred Stock for $90
Stockholder Rights Plan, expiration date	Nov. 09, 2016
Stockholder Rights Plan, redemption price per Right	0.001
Stock split ratio		2
(1/100th) [Member]
Class of Stock [Line Items]
Preferred Stock purchase price upon exercise of Rights	190		90
(1/200th) [Member]
Class of Stock [Line Items]
Preferred Stock purchase price upon exercise of Rights	95	45