License And Collaboration Agreement, Development Payment

No definition available.

Name:	til_LicenseAndCollaborationAgreementDevelopmentPayment
Namespace Prefix:	til_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

License And Collaboration Agreement, Reduction Of Research And Development Expense

+ References

No definition available.

+ Details

Name:	til_LicenseAndCollaborationAgreementReductionOfResearchAndDevelopmentExpense
Namespace Prefix:	til_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

License And Collaboration Agreement, Up Front Payment, Additional Accrual

+ References

No definition available.

+ Details

Name:	til_LicenseAndCollaborationAgreementUpFrontPaymentAdditionalAccrual
Namespace Prefix:	til_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

License And Collaboration Agreement, Upfront Payment

+ References

No definition available.

+ Details

Name:	til_LicenseAndCollaborationAgreementUpfrontPayment
Namespace Prefix:	til_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

License And Development Agreement, Development Cost, Period Cost

+ References

No definition available.

+ Details

Name:	til_LicenseAndDevelopmentAgreementDevelopmentCostPeriodCost
Namespace Prefix:	til_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Research and Development Expense, In Process

+ References

No definition available.

+ Details

Name:	til_ResearchAndDevelopmentExpenseInProcess
Namespace Prefix:	til_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479402/808-10-50-1

+ Details

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

- Definition

The net amount of research and development costs incurred for a fixed-price, best-efforts research and development cost-sharing arrangement with the Federal Government.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 912
-SubTopic 730
-Name Accounting Standards Codification
-Section 25
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479532/912-730-25-1

+ Details

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

- Details

Name:	srt_CounterpartyNameAxis=til_AxionBioInc.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ResearchAndDevelopmentArrangementContractToPerformForOthersByTypeAxis=til_CommercialDevelopmentAndRegulatoryMilestonesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

License and Collaboration Agreement with ImmuneOnco (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
	Apr. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2024	Mar. 31, 2026	Jan. 05, 2026	Aug. 31, 2025	Jul. 31, 2025
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development cost	$ 5,000
Additional accrual for prepayment of development costs										$ 5,000
In-process research and development		$ 0	$ 10,000		$ 0	$ 10,000
Axion
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Upfront payment							$ 10,000
Development cost				$ 5,000
Collaboration agreement costs incurred		0	14,100		300	18,400
In-process research and development			$ 10,000			$ 10,000
Axion \| Commercial, development and regulatory milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Development payment		$ 200			$ 200				$ 1,800		$ 10,000
Reduction of research and development expense								$ 1,600