Quarterly report pursuant to Section 13 or 15(d)

Debt (Debt Issuances - Senior Notes) (Details)

v2.4.1.9
Debt (Debt Issuances - Senior Notes) (Details) (USD $)
3 Months Ended 6 Months Ended 0 Months Ended 1 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Nov. 19, 2014
Nov. 30, 2014
Jun. 30, 2014
Oct. 31, 2014
Debt Instrument [Line Items]                
Cash dividends declared per share (in dollars per share) $ 17us-gaap_CommonStockDividendsPerShareDeclared $ 0.45us-gaap_CommonStockDividendsPerShareDeclared $ 17.5us-gaap_CommonStockDividendsPerShareDeclared $ 0.9us-gaap_CommonStockDividendsPerShareDeclared        
Discount on debt $ 3,929,000us-gaap_DebtInstrumentUnamortizedDiscount   $ 3,929,000us-gaap_DebtInstrumentUnamortizedDiscount       $ 2,081,000us-gaap_DebtInstrumentUnamortizedDiscount  
Special Cash Dividend                
Debt Instrument [Line Items]                
Cash dividends declared per share (in dollars per share) $ 16.50us-gaap_CommonStockDividendsPerShareDeclared
/ us-gaap_DividendsAxis
= klac_SpecialCashDividendMember
$ 0us-gaap_CommonStockDividendsPerShareDeclared
/ us-gaap_DividendsAxis
= klac_SpecialCashDividendMember
  $ 0us-gaap_CommonStockDividendsPerShareDeclared
/ us-gaap_DividendsAxis
= klac_SpecialCashDividendMember
$ 16.50us-gaap_CommonStockDividendsPerShareDeclared
/ us-gaap_DividendsAxis
= klac_SpecialCashDividendMember
$ 16.50us-gaap_CommonStockDividendsPerShareDeclared
/ us-gaap_DividendsAxis
= klac_SpecialCashDividendMember
   
Cash dividends           2,760,000,000us-gaap_DividendsCommonStockCash
/ us-gaap_DividendsAxis
= klac_SpecialCashDividendMember
   
Treasury Lock | Forward Contracts | Senior Notes | Derivatives Designated as Hedging Instruments | Cash Flow Hedging | Portion of senior notes                
Debt Instrument [Line Items]                
Derivative interest rate 4.626%us-gaap_DerivativeFixedInterestRate
/ us-gaap_DebtInstrumentAxis
= klac_PortionofSeniorNotesMember
/ us-gaap_DerivativeByNatureAxis
= us-gaap_ForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_TreasuryLockMember
/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis
= us-gaap_CashFlowHedgingMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_UnderlyingAssetClassAxis
= us-gaap_SeniorNotesMember
  4.626%us-gaap_DerivativeFixedInterestRate
/ us-gaap_DebtInstrumentAxis
= klac_PortionofSeniorNotesMember
/ us-gaap_DerivativeByNatureAxis
= us-gaap_ForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_TreasuryLockMember
/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis
= us-gaap_CashFlowHedgingMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_UnderlyingAssetClassAxis
= us-gaap_SeniorNotesMember
         
Notional amount of derivative               1,000,000,000invest_DerivativeNotionalAmount
/ us-gaap_DebtInstrumentAxis
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/ us-gaap_DerivativeByNatureAxis
= us-gaap_ForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
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/ us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis
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/ us-gaap_HedgingDesignationAxis
= us-gaap_DesignatedAsHedgingInstrumentMember
/ us-gaap_UnderlyingAssetClassAxis
= us-gaap_SeniorNotesMember
Senior Notes                
Debt Instrument [Line Items]                
Principal amount           2,500,000,000.0us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
   
Discount on debt           4,000,000us-gaap_DebtInstrumentUnamortizedDiscount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
   
Debt frequency of payment     semi-annually          
Offer to repurchase senior notes, percent of principal amount     101.00%us-gaap_DebtInstrumentRedemptionPricePercentage
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Fair value 2,600,000,000us-gaap_DebtInstrumentFairValue
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
  2,600,000,000us-gaap_DebtInstrumentFairValue
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
      893,700,000us-gaap_DebtInstrumentFairValue
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
 
Senior Notes | Standard & Poor's, BBplus Rating                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     0.25%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingStandardPoorsAxis
= us-gaap_StandardPoorsBBPlusRatingMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | Standard & Poor's, BB Rating                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     0.50%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingStandardPoorsAxis
= us-gaap_StandardPoorsBBRatingMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | Standard & Poor's, BB- Rating                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     0.75%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingStandardPoorsAxis
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/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | Standard & Poor's, B Plus or Below                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     1.00%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingStandardPoorsAxis
= us-gaap_StandardPoorsBPlusRatingMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | Moody's, Ba1 Rating                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     0.25%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingMoodysAxis
= us-gaap_MoodysBa1RatingMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | Moody's, Ba2 Rating                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     0.50%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingMoodysAxis
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/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | Moody's, Ba3 Rating                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     0.75%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingMoodysAxis
= us-gaap_MoodysBa3RatingMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | Moody's, B1 Rating                
Debt Instrument [Line Items]                
Decrease in credit rating, interest rate increase     1.00%klac_DebtInstrumentDecreaseinCreditRatingInterestRateAdjustment
/ us-gaap_CreditRatingMoodysAxis
= us-gaap_MoodysB1RatingMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
         
Senior Notes | 2018 Senior Notes                
Debt Instrument [Line Items]                
Principal amount           $ 750,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
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/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
   
Debt maturity date           2018