Sale Of Stock, Authorized, Amount

No definition available.

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- Definition

Sale Of Stock, Authorized, Period

+ References

No definition available.

+ Details

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- Definition

Sale Of Stock, Average Price Per Share

+ References

No definition available.

+ Details

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Namespace Prefix:	oncy_
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Balance Type:	na
Period Type:	duration

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480100/505-10-S45-3

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(20))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of cash paid for commissions during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 25
-Subparagraph (g)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-25

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for cost incurred directly with the issuance of an equity security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-15

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Cash received on stock transaction after deduction of issuance costs.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockConsiderationReceivedOnTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

Name:	us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- 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

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

- Details

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- Details

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- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=oncy_October2025AtTheMarketOfferingAgreementMember
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- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=oncy_August2024AtTheMarketOfferingAgreementMember
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Capital Stock - At-the-Market Offering Agreements (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2026	Mar. 31, 2026	Jun. 30, 2025	Jun. 30, 2025	Apr. 06, 2026	Oct. 17, 2025	Aug. 02, 2024
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.001
April 2026 ATM \| Jefferies LLC
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share)					$ 0.001
Authorized amount					$ 75,000
Sale of stock (in shares)	7,859,359
Proceeds from issuance of common stock	$ 7,152,000
Sale of stock, average price (in dollars per share)	$ 0.91
Net proceeds from sale of stock	$ 6,771,000
Payments of stock issuance costs	381,000
Payments of commissions	$ 215,000
October 2025 ATM
Subsidiary, Sale of Stock [Line Items]
Authorized amount						$ 50,000,000
Sale of stock (in shares)		7,446,574
Proceeds from issuance of common stock		$ 7,861,000
Sale of stock, average price (in dollars per share)		$ 1.06
Net proceeds from sale of stock		$ 7,614,000
Payments of stock issuance costs		247,000
Payments of commissions		$ 236,000
August 2024 ATM
Subsidiary, Sale of Stock [Line Items]
Authorized amount							$ 50,000,000
Authorized period							25 months
Sale of stock (in shares)			3,266,024	8,568,974
Proceeds from issuance of common stock			$ 1,823,000	$ 6,150,000
Sale of stock, average price (in dollars per share)			$ 0.56	$ 0.72
Net proceeds from sale of stock			$ 1,746,000	$ 5,929,000
Payments of stock issuance costs			77,000	221,000
Payments of commissions			$ 55,000	$ 185,000