Net Income Per Common Share - Additional Information (Detail) - shares	3 Months Ended	9 Months Ended
Oct. 01, 2023	Oct. 02, 2022	Oct. 01, 2023	Oct. 02, 2022
Employee Stock Option [Member]
Net Income Loss Per Common Share
Exercise of stock options	0.1	0.7	0.4	0.9

Stock issued during period shares sale of stock and exercise of stock options.

No definition available.

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Namespace Prefix:	ter_
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Balance Type:	na
Period Type:	duration