| 
           Debt  - Debt Issuances - Credit Facility (Details) (USD $)
  
         | 
        9 Months Ended | 
        1 Months Ended | 
      
      
        | 
           Mar. 31, 2015
 
          quarter 
         | 
        
           Nov. 30, 2014 
         | 
      
      
        | Term loans and revolving credit facility | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Number of consecutive quarters required to maintain ratio | 
        
4klac_DebtInstrumentCovenantComplianceNumberofConsecutiveQuarters / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Minimum interest expense coverage ratio | 
        
3.50klac_DebtInstrumentCovenantComplianceMinimumInterestExpenseCoverageRatio / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Credit facility, amount outstanding | 
        
$ 0us-gaap_LineOfCreditFacilityFairValueOfAmountOutstanding / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | Covenant compliance period, fiscal quarter ending December 31, 2014 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Number of consecutive quarters required to maintain ratio | 
        
4klac_DebtInstrumentCovenantComplianceNumberofConsecutiveQuarters / klac_CovenantCompliancePeriodAxis = klac_CovenantCompliancePeriod1Member / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | Covenant compliance period, fiscal quarters ending March 31, 2015 and June 30, 2015 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Maximum leverage ratio | 
        
4.25klac_DebtInstrumentCovenantComplianceMaximumLeverageRatio / klac_CovenantCompliancePeriodAxis = klac_CovenantCompliancePeriod2Member / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | Covenant compliance period, fiscal quarters ending September 30, 2015 and December 31, 2015 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Maximum leverage ratio | 
        
4.00klac_DebtInstrumentCovenantComplianceMaximumLeverageRatio / klac_CovenantCompliancePeriodAxis = klac_CovenantCompliancePeriod3Member / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | Covenant compliance period, fiscal quarters ending March 31, 2016 through September 30, 2016 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Maximum leverage ratio | 
        
3.75klac_DebtInstrumentCovenantComplianceMaximumLeverageRatio / klac_CovenantCompliancePeriodAxis = klac_CovenantCompliancePeriod4Member / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | Covenant compliance period, fiscal quarters ending December 31, 2016 through March 31, 2017 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Maximum leverage ratio | 
        
3.50klac_DebtInstrumentCovenantComplianceMaximumLeverageRatio / klac_CovenantCompliancePeriodAxis = klac_CovenantCompliancePeriod5Member / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | Covenant compliance period, thereafter | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Maximum leverage ratio | 
        
3.00klac_DebtInstrumentCovenantComplianceMaximumLeverageRatio / klac_CovenantCompliancePeriodAxis = klac_CovenantCompliancePeriod6Member / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember
 | 
         
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        | Term loans and revolving credit facility | LIBOR | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Basis spread on variable rate | 
        
1.25%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | LIBOR | Minimum | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Basis spread on variable rate | 
        
1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember
 | 
         
 | 
      
      
        | Term loans and revolving credit facility | LIBOR | Maximum | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Basis spread on variable rate | 
        
1.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LongtermDebtTypeAxis = klac_TermLoanandRevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember
 | 
         
 | 
      
      
        | Term Loans | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Principal amount | 
         
 | 
        
750,000,000us-gaap_DebtInstrumentFaceAmount / us-gaap_LongtermDebtTypeAxis = us-gaap_MediumTermNotesMember
 | 
      
      
        | Term of debt instrument | 
         
 | 
        5 years
 | 
      
      
        | Term Loans | Principal payment period, fiscal quarters ending March 31, 2015 - December 31, 2016 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Periodic principal payment | 
        
9,375,000us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentRedemptionPeriodAxis = us-gaap_DebtInstrumentRedemptionPeriodOneMember / us-gaap_LongtermDebtTypeAxis = us-gaap_MediumTermNotesMember
 | 
         
 | 
      
      
        | Term Loans | Principal payment period, fiscal quarters ending March 31, 2017 - December 31, 2017 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Periodic principal payment | 
        
14,063,000us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentRedemptionPeriodAxis = us-gaap_DebtInstrumentRedemptionPeriodTwoMember / us-gaap_LongtermDebtTypeAxis = us-gaap_MediumTermNotesMember
 | 
         
 | 
      
      
        | Term Loans | Principal payment period, fiscal quarters ending March 31, 2018 - December 31, 2019 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Periodic principal payment | 
        
18,750,000us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentRedemptionPeriodAxis = us-gaap_DebtInstrumentRedemptionPeriodThreeMember / us-gaap_LongtermDebtTypeAxis = us-gaap_MediumTermNotesMember
 | 
         
 | 
      
      
        | Term Loans | December 31, 2019 | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Periodic principal payment | 
        
487,500,000us-gaap_DebtInstrumentPeriodicPaymentPrincipal / us-gaap_DebtInstrumentRedemptionPeriodAxis = us-gaap_DebtInstrumentRedemptionPeriodFourMember / us-gaap_LongtermDebtTypeAxis = us-gaap_MediumTermNotesMember
 | 
         
 | 
      
      
        | Revolving credit facility | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Maximum borrowing capacity | 
         
 | 
        
$ 500,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember
 | 
      
      
        | Annual commitment fee on daily undrawn balance of revolving credit facility | 
        
0.15%us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember
 | 
         
 | 
      
      
        | Revolving credit facility | Minimum | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Annual commitment fee on daily undrawn balance of revolving credit facility | 
        
0.10%us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MinimumMember
 | 
         
 | 
      
      
        | Revolving credit facility | Maximum | 
         
 | 
         
 | 
      
      
        | Debt Instrument [Line Items] | 
         
 | 
         
 | 
      
      
        | Annual commitment fee on daily undrawn balance of revolving credit facility | 
        
0.25%us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_RangeAxis = us-gaap_MaximumMember
 | 
         
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