XML 50 R39.htm IDEA: XBRL DOCUMENT v3.22.1

Fair Value Measurement - Summary of Financial Instruments Recorded at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	$ 261,527	$ 217,609
U.S. Treasury securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	194,739	157,277
Certificates of deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	14,234	6,490
Corporate debt securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	32,712	36,327
Commercial paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	14,664	11,620
Asset-backed securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	5,178	5,895
Fair Value Measurements Recurring
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	355,885	368,688
Fair Value Measurements Recurring | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	94,358	151,079
Fair Value Measurements Recurring | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	261,527	217,609
Fair Value Measurements Recurring | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	0	0
Fair Value Measurements Recurring | Money market mutual funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	94,358	151,079
Fair Value Measurements Recurring | Money market mutual funds | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	94,358	151,079
Fair Value Measurements Recurring | Money market mutual funds | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	0	0
Fair Value Measurements Recurring | Money market mutual funds | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	0	0
Fair Value Measurements Recurring | U.S. Treasury securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	194,739	157,277
Fair Value Measurements Recurring | U.S. Treasury securities | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | U.S. Treasury securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	194,739	157,277
Fair Value Measurements Recurring | U.S. Treasury securities | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Certificates of deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	14,234	6,490
Fair Value Measurements Recurring | Certificates of deposit | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Certificates of deposit | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	14,234	6,490
Fair Value Measurements Recurring | Certificates of deposit | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Corporate debt securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	32,712	36,327
Fair Value Measurements Recurring | Corporate debt securities | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Corporate debt securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	32,712	36,327
Fair Value Measurements Recurring | Corporate debt securities | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Commercial paper
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	14,664	11,620
Fair Value Measurements Recurring | Commercial paper | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Commercial paper | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	14,664	11,620
Fair Value Measurements Recurring | Commercial paper | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Asset-backed securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	5,178	5,895
Fair Value Measurements Recurring | Asset-backed securities | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	0
Fair Value Measurements Recurring | Asset-backed securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	5,178	5,895
Fair Value Measurements Recurring | Asset-backed securities | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, 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

Money market funds fair value disclosure.

+ References

No definition available.

+ Details

Name:	ontf_MoneyMarketFundsFairValueDisclosure
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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26626-111562

+ 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

- Details

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

X

- Details

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

X

- Details

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

X

- Details

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

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_AssetBackedSecuritiesMember
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:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: