XML 116 R95.htm IDEA: XBRL DOCUMENT v2.4.1.9
Employee Benefit Plans - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended 1 Months Ended
Dec. 31, 2014
Plan
Age
Dec. 31, 2013
Dec. 31, 2012
Jun. 30, 2014
Defined Benefit Plan Disclosure [Line Items]        
Employee contribution to Company's profit sharing plan percentage 1.00%mksi_DefinedContributionPlanMinimumAnnualContributionsPerEmployeePercent      
Employee contribution to Company's profit sharing plan percentage 50.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent      
Minimum age limit for specified additional amount 50mksi_MinimumAgeLimitForSpecifiedAdditionalAmount      
Employers contribution percentage limit 50.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercentOfMatch      
Employees maximum contribution as a percentage of salary 6.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent      
Company's contributions $ 2,484us-gaap_PensionAndOtherPostretirementBenefitContributions $ 2,334us-gaap_PensionAndOtherPostretirementBenefitContributions $ 2,245us-gaap_PensionAndOtherPostretirementBenefitContributions  
Foreign defined benefit plan 1mksi_NumberOfForeignDefinedBenefitPensionPlans      
Bonus expense 14,434mksi_EmployeePerformanceAwardBonusExpense 16,006mksi_EmployeePerformanceAwardBonusExpense 8,855mksi_EmployeePerformanceAwardBonusExpense  
Supplemental retirement benefits cost 2,258mksi_SupplementalRetirementBenefitsCost 4,988mksi_SupplementalRetirementBenefitsCost 3,454mksi_SupplementalRetirementBenefitsCost  
Accumulated benefit obligation 8,941mksi_SupplementalRetirementBenefitsAccumulatedBenefitObligation 21,403mksi_SupplementalRetirementBenefitsAccumulatedBenefitObligation    
Chief Executive Officer [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Payment related to accrued supplemental retirement benefits       13,921us-gaap_DefinedBenefitPlanBenefitsPaid
/ us-gaap_TitleOfIndividualAxis
= us-gaap_ChiefExecutiveOfficerMember
Other Current Liabilities [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Accumulated benefit obligation   14,517mksi_SupplementalRetirementBenefitsAccumulatedBenefitObligation
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherCurrentLiabilitiesMember		    
Other Noncurrent Liabilities [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Accumulated benefit obligation   $ 6,886mksi_SupplementalRetirementBenefitsAccumulatedBenefitObligation
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_OtherNoncurrentLiabilitiesMember