XML 82 R71.htm IDEA: XBRL DOCUMENT
v3.21.1

Share Repurchase Authorization - Textual (Details) - USD ($) | Mar. 27, 2021 | Nov. 30, 2020
--- | --- | ---
Shares Repurchase Authorization [Line Items] |  |
Amount available for future repurchase | $ 100,000,000 | $ 28,000,000
Maximum [Member] |  |
Shares Repurchase Authorization [Line Items] |  |
Stock repurchase, authorized amount |  | $ 100,000,000

X
- Definition Shares repurchase authorization. + References No definition available. + Details
Name: | onto_SharesRepurchaseAuthorizationLineItems
Namespace Prefix: | onto_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount remaining of a stock repurchase plan authorized. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |