Earnings Per Common Share Attributable to Teradyne - Additional Information (Detail) - shares shares in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 27, 2026 |
Sep. 28, 2025 |
Sep. 27, 2026 |
Sep. 28, 2025 |
|
| Employee Stock Option [Member] | ||||
| Net Income Loss Per Common Share | ||||
| Exercise of stock options | 0.1 | 0.2 | 0.1 | 0.7 |