Disclosure - Restructuring (Additional Information) (Details) $ in Thousands	3 Months Ended
Apr. 01, 2023 USD ($)
Restructuring Charges [Abstract]
Restructuring cost in cost of goods sold	$ 2,279
Restructuring cost in operating expenses	$ 2,034

Restructuring cost recored to cost of goods sold for inventory write-downs.

No definition available.

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Namespace Prefix:	onto_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration