Earnings Per Common Share Attributable to Teradyne - Additional Information (Detail) - shares shares in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 28, 2026 |
Jun. 29, 2025 |
Jun. 28, 2026 |
Jun. 29, 2025 |
|
| Employee Stock Option [Member] | ||||
| Net Income Loss Per Common Share | ||||
| Exercise of stock options | 0.1 | 1.4 | 0.1 | 1.9 |