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Segments and Geographic Information - Operating Results By Segment (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 25, 2021 USD ($) segment | Dec. 26, 2020 USD ($) | Dec. 28, 2019 USD ($)
Segment Reporting [Abstract] |  |  |
Number of reportable segments | segment | 2 |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | $ 769,674 | $ 693,616 | $ 589,464
Gross profit | $ 322,767 | $ 287,920 | $ 237,496
Gross margin | 41.90% | 41.50% | 40.30%
Probe Cards |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | $ 633,281 | $ 581,739 | $ 491,363
Systems |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 136,393 | 111,877 | 98,101
Operating Segments | Probe Cards |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | 633,281 | 581,739 | 491,363
Gross profit | $ 279,873 | $ 263,215 | $ 211,382
Gross margin | 44.20% | 45.20% | 43.00%
Operating Segments | Systems |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | $ 136,393 | $ 111,877 | $ 98,101
Gross profit | $ 65,834 | $ 51,835 | 50,927
Gross margin | 48.30% | 46.30% |
Corporate and Other |  |  |
Segment Reporting Information [Line Items] |  |  |
Revenues | $ 0 | $ 0 | 0
Gross profit | $ (22,940) | $ (27,130) | $ (24,813)
Gross margin | 0.00% | 0.00% | 0.00%

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