| Business Combinations  - Pro Forma Information (Details) - Orbotech and three privately-held companies - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 
|---|---|---|
| Mar. 31, 2019 | Mar. 31, 2019 | |
| Business Acquisition | ||
| Revenues | $ 1,160,678 | $ 4,165,268 | 
| Net income attributable to KLA | $ 192,577 | $ 1,033,653 | 
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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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