XML 58 R53.htm IDEA: XBRL DOCUMENT v2.4.1.9
Employee Benefit Plans - Schedule of Net Periodic Benefit Cost of Swiss Plan (Detail) (Swiss Plan [Member], USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 27, 2014
Dec. 28, 2013
Defined Benefit Plan Disclosure [Line Items]    
Net Periodic Benefit Cost, Total $ 897us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost $ 972us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost
Net Periodic Benefit Costs [Member]
   
Defined Benefit Plan Disclosure [Line Items]    
Service cost 749us-gaap_DefinedBenefitPlanServiceCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= cohu_NetPeriodicBenefitCostsMember
/ us-gaap_PlanNameAxis
= cohu_SwissDefinedBenefitPlanMember
841us-gaap_DefinedBenefitPlanServiceCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= cohu_NetPeriodicBenefitCostsMember
/ us-gaap_PlanNameAxis
= cohu_SwissDefinedBenefitPlanMember
Interest cost 491us-gaap_DefinedBenefitPlanInterestCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= cohu_NetPeriodicBenefitCostsMember
/ us-gaap_PlanNameAxis
= cohu_SwissDefinedBenefitPlanMember
398us-gaap_DefinedBenefitPlanInterestCost
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= cohu_NetPeriodicBenefitCostsMember
/ us-gaap_PlanNameAxis
= cohu_SwissDefinedBenefitPlanMember
Expected return on assets $ (343)us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= cohu_NetPeriodicBenefitCostsMember
/ us-gaap_PlanNameAxis
= cohu_SwissDefinedBenefitPlanMember
$ (267)us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets
/ us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis
= cohu_NetPeriodicBenefitCostsMember
/ us-gaap_PlanNameAxis
= cohu_SwissDefinedBenefitPlanMember