Quarterly report pursuant to Section 13 or 15(d)

Debt - Debt Redemption (Details)

v2.4.1.9
Debt - Debt Redemption (Details) (USD $)
 3 Months Ended 9 Months Ended
Dec. 31, 2014
Mar. 31, 2015
Nov. 30, 2014
Debt Instrument [Line Items]      
Pre-tax net loss on extinguishment of debt $ 131,700,000us-gaap_GainsLossesOnExtinguishmentOfDebt $ 131,700,000us-gaap_GainsLossesOnExtinguishmentOfDebt  
Senior Notes | 2018 Senior Notes      
Debt Instrument [Line Items]      
Principal amount of debt redeemed 750,000,000us-gaap_DebtInstrumentRepurchasedFaceAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Pre-tax net loss on extinguishment of debt 131,700,000us-gaap_GainsLossesOnExtinguishmentOfDebt
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Not Designated as Hedging Instrument | Senior Notes | Treasury Lock | Forward Contracts | 2018 Senior Notes      
Debt Instrument [Line Items]      
Derivative, gain on derivative 1,200,000us-gaap_DerivativeGainOnDerivative
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_DerivativeByNatureAxis
= us-gaap_ForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_TreasuryLockMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ us-gaap_UnderlyingAssetClassAxis
= us-gaap_SeniorNotesMember 		   
Notional amount of derivative     $ 750,000,000invest_DerivativeNotionalAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_DerivativeByNatureAxis
= us-gaap_ForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_TreasuryLockMember
/ us-gaap_HedgingDesignationAxis
= us-gaap_NondesignatedMember
/ us-gaap_UnderlyingAssetClassAxis
= us-gaap_SeniorNotesMember