| Business Combinations  - Pro Forma Information (Details) - Orbotech and three privately-held companies $ in Thousands | 3 Months Ended | 
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| Sep. 30, 2018  USD ($) | |
| Business Acquisition | |
| Revenues | $ 1,348,197 | 
| Net income attributable to KLA | $ 376,634 | 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Details 
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