XML 56 R46.htm IDEA: XBRL DOCUMENT v3.23.3

Fair Value Measurement - Schedule of Financial Instruments Recorded at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value (Recurring) [Line Items]
Fair Value	$ 202,935	$ 301,125
U.S. Treasury securities
Fair Value (Recurring) [Line Items]
Fair Value	159,050	219,104
U.S. Agency securities
Fair Value (Recurring) [Line Items]
Fair Value	29,330	19,264
Certificates of deposit
Fair Value (Recurring) [Line Items]
Fair Value	3,365	26,509
Corporate debt securities
Fair Value (Recurring) [Line Items]
Fair Value	1,684	13,848
Commercial paper
Fair Value (Recurring) [Line Items]
Fair Value	9,506	22,400
Fair Value Measurements Recurring
Fair Value (Recurring) [Line Items]
Cash equivalents - money market mutual funds	8,842	5,608
Total cash equivalents and marketable securities	211,777	306,733
Fair Value Measurements Recurring | Level 1
Fair Value (Recurring) [Line Items]
Cash equivalents - money market mutual funds	8,842	5,608
Total cash equivalents and marketable securities	8,842	5,608
Fair Value Measurements Recurring | Level 2
Fair Value (Recurring) [Line Items]
Cash equivalents - money market mutual funds	0	0
Total cash equivalents and marketable securities	202,935	301,125
Fair Value Measurements Recurring | Level 3
Fair Value (Recurring) [Line Items]
Cash equivalents - money market mutual funds	0	0
Total cash equivalents and marketable securities	0	0
Fair Value Measurements Recurring | U.S. Treasury securities
Fair Value (Recurring) [Line Items]
Fair Value	159,050	219,104
Fair Value Measurements Recurring | U.S. Treasury securities | Level 1
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | U.S. Treasury securities | Level 2
Fair Value (Recurring) [Line Items]
Fair Value	159,050	219,104
Fair Value Measurements Recurring | U.S. Treasury securities | Level 3
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | U.S. Agency securities
Fair Value (Recurring) [Line Items]
Fair Value	29,330	19,264
Fair Value Measurements Recurring | U.S. Agency securities | Level 1
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | U.S. Agency securities | Level 2
Fair Value (Recurring) [Line Items]
Fair Value	29,330	19,264
Fair Value Measurements Recurring | U.S. Agency securities | Level 3
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | Certificates of deposit
Fair Value (Recurring) [Line Items]
Fair Value	3,365	26,509
Fair Value Measurements Recurring | Certificates of deposit | Level 1
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | Certificates of deposit | Level 2
Fair Value (Recurring) [Line Items]
Fair Value	3,365	26,509
Fair Value Measurements Recurring | Certificates of deposit | Level 3
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | Corporate debt securities
Fair Value (Recurring) [Line Items]
Fair Value	1,684	13,848
Fair Value Measurements Recurring | Corporate debt securities | Level 1
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | Corporate debt securities | Level 2
Fair Value (Recurring) [Line Items]
Fair Value	1,684	13,848
Fair Value Measurements Recurring | Corporate debt securities | Level 3
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | Commercial paper
Fair Value (Recurring) [Line Items]
Fair Value	9,506	22,400
Fair Value Measurements Recurring | Commercial paper | Level 1
Fair Value (Recurring) [Line Items]
Fair Value	0	0
Fair Value Measurements Recurring | Commercial paper | Level 2
Fair Value (Recurring) [Line Items]
Fair Value	9,506	22,400
Fair Value Measurements Recurring | Commercial paper | Level 3
Fair Value (Recurring) [Line Items]
Fair Value	$ 0	$ 0

X

- Definition

Cash equivalents and available for sale debt securities fair value disclosure.

+ References

No definition available.

+ Details

Name:	ontf_CashEquivalentsAndAvailableForSaleDebtSecuritiesFairValueDisclosure
Namespace Prefix:	ontf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481830/320-10-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479130/326-30-45-1

+ Details

Name:	us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

+ References

No definition available.

+ Details

Name:	us-gaap_MoneyMarketFundsAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: