Quarterly report pursuant to Section 13 or 15(d)

Debt (Schedule of Debt) (Details)

v2.4.1.9
Debt (Schedule of Debt) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Jun. 30, 2014
Nov. 30, 2014
Oct. 31, 2014
Debt Instrument [Line Items]        
Total debt, gross $ 3,250,000us-gaap_DebtInstrumentCarryingAmount $ 750,000us-gaap_DebtInstrumentCarryingAmount    
Unamortized discount (3,929)us-gaap_DebtInstrumentUnamortizedDiscount (2,081)us-gaap_DebtInstrumentUnamortizedDiscount    
Total debt, net of discount 3,246,071us-gaap_LongTermDebt 747,919us-gaap_LongTermDebt    
Current portion of long-term debt 37,500us-gaap_LongTermDebtCurrent 0us-gaap_LongTermDebtCurrent    
Long-term debt 3,208,571us-gaap_LongTermDebtNoncurrent 747,919us-gaap_LongTermDebtNoncurrent    
Senior Notes        
Debt Instrument [Line Items]        
Unamortized discount     (4,000)us-gaap_DebtInstrumentUnamortizedDiscount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		 
Senior Notes | Fixed-rate 6.900% Senior notes due on May 1, 2018        
Debt Instrument [Line Items]        
Total debt, gross 0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		750,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Effective interest rate   7.001%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Stated interest rate 6.90%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		6.90%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueMay12018Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Senior Notes | Fixed-rate 2.375% Senior notes due on November 1, 2017        
Debt Instrument [Line Items]        
Total debt, gross 250,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12017Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12017Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Effective interest rate 2.396%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12017Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Stated interest rate 2.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12017Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Senior Notes | Fixed-rate 3.375% Senior notes due on November 1, 2019        
Debt Instrument [Line Items]        
Total debt, gross 250,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Effective interest rate 3.377%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Stated interest rate 3.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12019Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Senior Notes | Fixed-rate 4.125% Senior notes due on November 1, 2021        
Debt Instrument [Line Items]        
Total debt, gross 500,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12021Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12021Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Effective interest rate 4.128%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12021Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Stated interest rate 4.125%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12021Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Senior Notes | Fixed-rate 4.650% Senior notes due on November 1, 2024        
Debt Instrument [Line Items]        
Total debt, gross 1,250,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12024Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		[1] 0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12024Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		[1]    
Effective interest rate 4.682%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12024Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		[1]      
Stated interest rate 4.65%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12024Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		[1]     4.65%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12024Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Senior Notes | Fixed-rate 5.650% Senior notes due on November 1, 2034        
Debt Instrument [Line Items]        
Total debt, gross 250,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12034Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12034Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		   
Effective interest rate 5.67%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12034Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Stated interest rate 5.65%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= klac_SeniorNotesDueNovember12034Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		     
Term Loans        
Debt Instrument [Line Items]        
Total debt, gross $ 750,000us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_MediumTermNotesMember 		$ 0us-gaap_DebtInstrumentCarryingAmount
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_MediumTermNotesMember 		   
[1] The effective interest rate disclosed above for this series of Senior Notes excludes the impact of the treasury rate lock hedge discussed below. The effective interest rate including the impact of the treasury rate lock hedge was 4.626%.