| Segment Reporting and Geographic Information (Tables)
 | 6 Months Ended | 
| Dec. 31, 2019 | 
|---|
| Segment Reporting [Abstract] |  | 
| Summary Of Results for Reportable Segments | 
The following is a summary of results for each of our four reportable segments for the indicated periods:
 
|  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|   | Three Months Ended December 31,
 |   | Six Months Ended December 31,
 |  
| (In thousands) | 2019 |   | 2018 |   | 2019 |   | 2018 |  
| Semiconductor Process Control: |   |   |   |   |   |   |   |  
| Revenue | $ | 1,247,430 | 
 |   | $ | 1,094,013 | 
 |   | $ | 2,411,062 | 
 |   | $ | 2,163,972 | 
 |  
| Segment gross margin | 795,730 | 
 |   | 702,119 | 
 |   | 1,538,072 | 
 |   | 1,404,350 | 
 |  
| Specialty Semiconductor Process: |   |   |   |   |   |   |   |  
| Revenue | 75,106 | 
 |   | — | 
 |   | 144,245 | 
 |   | — | 
 |  
| Segment gross margin | 41,333 | 
 |   | — | 
 |   | 79,497 | 
 |   | — | 
 |  
| PCB, Display and Component Inspection: |   |   |   |   |   |   |   |  
| Revenue | 186,279 | 
 |   | 26,110 | 
 |   | 364,831 | 
 |   | 49,725 | 
 |  
| Segment gross margin | 82,538 | 
 |   | 10,555 | 
 |   | 158,606 | 
 |   | 21,088 | 
 |  
| Other: |   |   |   |   |   |   |   |  
| Revenue | 517 | 
 |   | — | 
 |   | 2,748 | 
 |   | — | 
 |  
| Segment gross margin | 117 | 
 |   | — | 
 |   | 770 | 
 |   | — | 
 |  
| Totals: |   |   |   |   |   |   |   |  
| Revenue | $ | 1,509,332 | 
 |   | $ | 1,120,123 | 
 |   | $ | 2,922,886 | 
 |   | $ | 2,213,697 | 
 |  
| Segment gross margin | $ | 919,718 | 
 |   | $ | 712,674 | 
 |   | $ | 1,776,945 | 
 |   | $ | 1,425,438 | 
 | 
 | 
| Reconciliation of Total Reportable Segments Revenue to Total Revenue | 
The following table reconciles total reportable segment revenue to total revenue for the indicated periods:
|  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|   | Three Months Ended December 31,
 |   | Six Months Ended December 31,
 |  
| (In thousands) | 2019 |   | 2018 |   | 2019 |   | 2018 |  
| Total revenue for reportable segments | $ | 1,509,332 | 
 |   | $ | 1,120,123 | 
 |   | $ | 2,922,886 | 
 |   | $ | 2,213,697 | 
 |  
| Corporate allocations and effects of foreign exchange rates | 121 | 
 |   | (225 | ) |   | (19 | ) |   | (539 | ) |  
| Total revenue | $ | 1,509,453 | 
 |   | $ | 1,119,898 | 
 |   | $ | 2,922,867 | 
 |   | $ | 2,213,158 | 
 | 
 | 
| Reconciliation of Total Segment Gross Margin to Total Income Before Income Taxes | 
The following table reconciles total segment gross margin to total income before income taxes for the indicated periods:
|  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|   | Three Months Ended December 31,
 |   | Six Months Ended December 31,
 |  
| (In thousands) | 2019 |   | 2018 |   | 2019 |   | 2018 |  
| Total segment gross margin  | $ | 919,718 | 
 |   | $ | 712,674 | 
 |   | $ | 1,776,945 | 
 |   | $ | 1,425,438 | 
 |  
| 
Acquisition-related charges, corporate allocations, and effects of foreign exchange rates(1)
 | 43,883 | 
 |   | 1,036 | 
 |   | 91,937 | 
 |   | 1,927 | 
 |  
| Research and development | 220,751 | 
 |   | 165,903 | 
 |   | 431,331 | 
 |   | 319,433 | 
 |  
| Selling, general and administrative | 192,253 | 
 |   | 112,462 | 
 |   | 380,598 | 
 |   | 226,900 | 
 |  
| Interest expense | 40,472 | 
 |   | 26,538 | 
 |   | 80,822 | 
 |   | 52,900 | 
 |  
| Other expense (income), net | (2,568 | ) |   | (9,228 | ) |   | (4,186 | ) |   | (19,253 | ) |  
| Income before income taxes | $ | 424,927 | 
 |   | $ | 415,963 | 
 |   | $ | 796,443 | 
 |   | $ | 843,531 | 
 |  __________________ (1) Acquisition-related charges primarily include amortization of intangible assets, amortization of inventory fair value adjustments, and other acquisition-related costs classified or presented as part of costs of revenues.  | 
| Revenues by Geographic Region | The following is a summary of revenues by geographic region, based on ship-to location, for the indicated periods: 
|  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| (Dollar amounts in thousands) | Three Months Ended December 31, |   | Six Months Ended December 31, |  
| 2019 |   | 2018 |   | 2019 |   | 2018 |  
| Revenues: |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |  
| Taiwan | $ | 447,083 | 
 | 
 | 30 | % | 
 | $ | 266,534 | 
 | 
 | 24 | % | 
 | $ | 833,812 | 
 | 
 | 28 | % | 
 | $ | 520,971 | 
 | 
 | 24 | % |  
| China | 381,752 | 
 | 
 | 25 | % | 
 | 269,878 | 
 | 
 | 24 | % | 
 | 727,608 | 
 | 
 | 25 | % | 
 | 610,012 | 
 | 
 | 28 | % |  
| Japan | 194,804 | 
 | 
 | 13 | % | 
 | 180,283 | 
 | 
 | 16 | % | 
 | 401,015 | 
 |   | 14 | % | 
 | 315,861 | 
 |   | 14 | % |  
| Korea | 181,948 | 
 | 
 | 12 | % | 
 | 126,968 | 
 | 
 | 11 | % | 
 | 379,398 | 
 | 
 | 13 | % | 
 | 280,469 | 
 | 
 | 13 | % |  
| North America | 158,517 | 
 | 
 | 11 | % | 
 | 150,113 | 
 | 
 | 13 | % | 
 | 340,500 | 
 | 
 | 12 | % | 
 | 252,242 | 
 | 
 | 11 | % |  
| Europe and Israel | 97,466 | 
 | 
 | 6 | % | 
 | 80,618 | 
 | 
 | 7 | % | 
 | 156,849 | 
 | 
 | 5 | % | 
 | 152,287 | 
 | 
 | 7 | % |  
| Rest of Asia | 47,883 | 
 | 
 | 3 | % | 
 | 45,504 | 
 | 
 | 5 | % | 
 | 83,685 | 
 | 
 | 3 | % | 
 | 81,316 | 
 | 
 | 3 | % |  
| Total | $ | 1,509,453 | 
 |   | 100 | % |   | $ | 1,119,898 | 
 |   | 100 | % |   | $ | 2,922,867 | 
 |   | 100 | % |   | $ | 2,213,158 | 
 |   | 100 | % | 
 | 
| Revenues by Major Products | The following is a summary of revenues by major products for the indicated periods: 
|  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| (Dollar amounts in thousands) | Three Months Ended December 31, |   | Six Months Ended December 31, |  
| 2019 |   | 2018 |   | 2019 |   | 2018 |  
| Revenues: |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |  
| Wafer Inspection | $ | 606,131 | 
 |   | 40 | % |   | $ | 478,553 | 
 |   | 43 | % |   | $ | 1,054,405 | 
 |   | 36 | % |   | $ | 925,845 | 
 |   | 42 | % |  
| Patterning | 289,078 | 
 |   | 19 | % |   | 284,496 | 
 |   | 25 | % |   | 671,736 | 
 |   | 23 | % |   | 588,497 | 
 |   | 26 | % |  
| Specialty Semiconductor Process | 60,941 | 
 |   | 4 | % |   | — | 
 |   | — | % |   | 117,811 | 
 |   | 4 | % |   | — | 
 |   | — | % |  
| PCB, Display and Component Inspection | 129,235 | 
 |   | 9 | % |   | 22,996 | 
 |   | 2 | % |   | 249,595 | 
 |   | 9 | % |   | 43,831 | 
 |   | 2 | % |  
| Services | 364,903 | 
 |   | 24 | % |   | 267,697 | 
 |   | 24 | % |   | 720,342 | 
 |   | 24 | % |   | 531,730 | 
 |   | 24 | % |  
| Other | 59,165 | 
 |   | 4 | % |   | 66,156 | 
 |   | 6 | % |   | 108,978 | 
 |   | 4 | % |   | 123,255 | 
 |   | 6 | % |  
| Total | $ | 1,509,453 | 
 |   | 100 | % |   | $ | 1,119,898 | 
 |   | 100 | % |   | $ | 2,922,867 | 
 |   | 100 | % |   | $ | 2,213,158 | 
 |   | 100 | % | 
 | 
| Long-Lived Assets by Geographic Region | 
Land, property and equipment, net by geographic region as of the dates indicated below were as follows: 
 
|  |  
|  |  |  |  |  |  |  |  |  
| (In thousands) | As of December 31, 2019
 |   | As of June 30, 2019
 |  
| Land, property and equipment, net: |   |   |   |  
| United States | $ | 297,938 | 
 |   | $ | 253,255 | 
 |  
| Singapore | 53,510 | 
 |   | 49,523 | 
 |  
| Israel | 59,943 | 
 |   | 66,082 | 
 |  
| Europe | 59,843 | 
 |   | 62,027 | 
 |  
| Rest of Asia | 18,746 | 
 |   | 17,912 | 
 |  
| Total | $ | 489,980 | 
 |   | $ | 448,799 | 
 | 
 |