XML 65 R38.htm IDEA: XBRL DOCUMENT
v3.20.1

Accumulated Other Comprehensive Loss (Tables) | 3 Months Ended
--- | ---
Mar. 28, 2020
Accumulated Other Comprehensive Loss [Abstract] |
Components of Accumulated Other Comprehensive Loss, Net of Tax | The components of accumulated other comprehensive loss, net of tax at March 28, 2020, as well as the activity for the three months ended March 28, 2020, were as follows:
|  | Accumulated Foreign Currency Translation Adjustment |  |  | Accumulated Net Unrealized Loss on Available-For-Sale Marketable Securities |  |  | Accumulated Other Comprehensive Loss |
Balance at December 31, 2019 |  | $ | 564 |  |  | $ | 34 |  |  | $ | 598 |
Net current period other comprehensive loss |  |  | 2,231 |  |  |  | 526 |  |  |  | 2,757 |
Reclassifications |  |  | — |  |  |  | — |  |  |  | — |
Balance at March 28, 2020 |  | $ | 2,795 |  |  | $ | 560 |  |  | $ | 3,355 |

X
- Definition Accumulated Other Comprehensive Loss [Abstract] + References No definition available. + Details
Name: | onto_AccumulatedOtherComprehensiveLossAbstract
Namespace Prefix: | onto_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the components of accumulated other comprehensive income (loss). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=118930883&loc=SL7669686-108580 + Details
Name: | us-gaap_ScheduleOfAccumulatedOtherComprehensiveIncomeLossTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration