Quarterly report pursuant to Section 13 or 15(d)

Income Taxes (Details)

v2.4.1.9
Income Taxes (Details) (USD $)
 3 Months Ended 9 Months Ended 3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Mar. 31, 2015
Mar. 31, 2014
Jun. 30, 2015
Jun. 30, 2015
Income Taxes [Line Items]              
Income before income taxes $ 166,454,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments   $ 251,246,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments $ 259,193,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments $ 567,855,000us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments    
Provision for income taxes 34,816,000us-gaap_IncomeTaxExpenseBenefit   47,665,000us-gaap_IncomeTaxExpenseBenefit 35,054,000us-gaap_IncomeTaxExpenseBenefit 113,831,000us-gaap_IncomeTaxExpenseBenefit    
Effective tax rate 20.90%us-gaap_EffectiveIncomeTaxRateContinuingOperations   19.00%us-gaap_EffectiveIncomeTaxRateContinuingOperations 13.50%us-gaap_EffectiveIncomeTaxRateContinuingOperations 20.00%us-gaap_EffectiveIncomeTaxRateContinuingOperations    
Pre-tax net loss on extinguishment of debt   131,700,000us-gaap_GainsLossesOnExtinguishmentOfDebt   131,700,000us-gaap_GainsLossesOnExtinguishmentOfDebt      
Tax rate reconciliation, deduction, executive deferred savings plan 2,100,000klac_EffectiveIncomeTaxRateReconciliationDeductionExecutiveDeferredSavingsPlanAmount       3,200,000klac_EffectiveIncomeTaxRateReconciliationDeductionExecutiveDeferredSavingsPlanAmount    
Tax rate reconciliation, deduction, inter-company dividends 3,800,000us-gaap_IncomeTaxReconciliationDeductionsDividends            
Tax rate comparison, deduction, expiration of statute of limitations     5,500,000klac_IncomeTaxRateComparisonDeductionExpirationofStatuteofLimitations        
Tax rate comparison, deduction, foreign earnings     2,100,000klac_IncomeTaxRateComparisonDeductionForeignEarnings        
Tax rate comparison, deduction, executive deferred savings plan 1,300,000klac_EffectiveIncomeTaxRateComparisonDeductionExecutiveDeferredSavingsPlan            
Tax rate comparison, deduction, inter-company dividends 3,800,000klac_EffectiveIncomeTaxRateComparisonDeductionDividends            
Decrease in tax expense as compared to prior year period, $131.7 million pre-tax net loss on extinguishment of debt, amount       45,200,000klac_IncomeTaxRateComparisonDeductionGainLossOnExtinguishmentOfDebtAmount      
Unrecognized tax benefits, reduction in next twelve months resulting from lapse of applicable statute of limitations         5,500,000us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations    
Decrease in tax expense as compared to prior year period, increase in the proportion of the company's earnings generated in jurisdictions with tax rates lower than the US statutory rate         4,900,000klac_IncomeTaxRateComparisonTaxExemptChangeInFairValueOfAssetsOfDeferredSavingsPlan    
Decrease in unrecognized tax benefits is reasonably possible $ 22,900,000klac_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible     $ 22,900,000klac_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible      
Forecast              
Income Taxes [Line Items]              
Estimated effective tax rate           22.00%klac_EstimatedEffectiveTaxRate
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember 		17.00%klac_EstimatedEffectiveTaxRate
/ us-gaap_StatementScenarioAxis
= us-gaap_ScenarioForecastMember