XML 22 R43.htm IDEA: XBRL DOCUMENT v2.4.1.9
Industry Segments - Schedule of Customer Concentration to Consolidated Net Sales (Detail)
3 Months Ended
Mar. 28, 2015
Customer
Mar. 29, 2014
Customer
Segment Reporting Information [Line Items]    
Customers individually accounting for more than 10% of consolidated net sales 2cohu_NumberOfCustomerAccountedForMoreThanTenPercentageOfNetSales 2cohu_NumberOfCustomerAccountedForMoreThanTenPercentageOfNetSales
Customer Concentration Risk [Member] | Consolidated Net Sales [Member]    
Segment Reporting Information [Line Items]    
Percentage of consolidated net sales 31.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember
27.00%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= us-gaap_SalesRevenueNetMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_CustomerConcentrationRiskMember