Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Details)

v2.4.1.9
Income Taxes (Details) (USD $)
 3 Months Ended 6 Months Ended 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Jun. 30, 2015
Jun. 30, 2015
Operating Loss Carryforwards            
Income (loss) before income taxes $ (6,268,000)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments $ 176,745,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments $ 92,739,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments $ 316,609,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments    
Provision for (benefit from) income taxes (26,536,000)us-gaap_IncomeTaxExpenseBenefit 37,499,000us-gaap_IncomeTaxExpenseBenefit 238,000us-gaap_IncomeTaxExpenseBenefit 66,166,000us-gaap_IncomeTaxExpenseBenefit    
Effective tax rate 423.40%us-gaap_EffectiveIncomeTaxRateContinuingOperations 21.20%us-gaap_EffectiveIncomeTaxRateContinuingOperations 0.30%us-gaap_EffectiveIncomeTaxRateContinuingOperations 20.90%us-gaap_EffectiveIncomeTaxRateContinuingOperations    
Pre-tax net loss on extinguishment of debt 131,700,000us-gaap_GainsLossesOnExtinguishmentOfDebt   131,700,000us-gaap_GainsLossesOnExtinguishmentOfDebt      
Decrease in tax expense, loss on extinguishment of debt, amount 45,800,000klac_EffectiveIncomeTaxRateReconciliationDeductionGainLossOnExtinguishmentOfDebtAmount          
Decrease in tax expense, reinstatement of the U.S. federal research credit 10,400,000us-gaap_IncomeTaxReconciliationTaxCreditsResearch          
Decrease in tax expense as compared to prior year period, loss on extinguishment of debt, amount 45,800,000klac_IncomeTaxRateComparisonDeductionGainLossOnExtinguishmentOfDebtAmount   45,800,000klac_IncomeTaxRateComparisonDeductionGainLossOnExtinguishmentOfDebtAmount      
Decrease in tax expense as compared to prior year period, reinstatement of the U.S. federal research credit 8,300,000klac_IncomeTaxRateComparisonTaxCreditResearchAmount   3,500,000klac_IncomeTaxRateComparisonTaxCreditResearchAmount      
Decrease in tax expense as compared to prior year period, non-taxable increase in fair value of assets held within Executive Deferred Savings Plan       4,500,000klac_IncomeTaxRateComparisonTaxExemptChangeInFairValueOfAssetsOfDeferredSavingsPlan    
Unrecognized tax benefits, reduction in next twelve months resulting from lapse of applicable statute of limitations     $ 11,600,000us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations      
Forecast            
Operating Loss Carryforwards            
Estimated effective tax rate         22.00%klac_EstimatedEffectiveTaxRate
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember 		19.00%klac_EstimatedEffectiveTaxRate
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= us-gaap_ScenarioForecastMember