Beneficial ownership limitation notice period.

No definition available.

Name:	tsha_BeneficialOwnershipLimitationNoticePeriod
Namespace Prefix:	tsha_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase or decrease in beneficial ownership limitation percentage.

+ References

No definition available.

+ Details

Name:	tsha_IncreaseOrDecreaseInBeneficialOwnershipLimitationPercentage
Namespace Prefix:	tsha_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of additional warrants issued upon exercise of underwriters option.

+ References

No definition available.

+ Details

Name:	tsha_NumberOfAdditionalWarrantsIssuedUponExerciseOfUnderwritersOption
Namespace Prefix:	tsha_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of aggregate shares beneficially owned.

+ References

No definition available.

+ Details

Name:	tsha_PercentageOfAggregateSharesBeneficiallyOwned
Namespace Prefix:	tsha_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of combined voting power beneficially owned.

+ References

No definition available.

+ Details

Name:	tsha_PercentageOfCombinedVotingPowerBeneficiallyOwned
Namespace Prefix:	tsha_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Proceeds from issuance of common stock net.

+ References

No definition available.

+ Details

Name:	tsha_ProceedsFromIssuanceOfCommonStockNet
Namespace Prefix:	tsha_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Underwriter agreed to purchase share price of per share.

+ References

No definition available.

+ Details

Name:	tsha_UnderwriterAgreedToPurchaseSharePriceOfPerShare
Namespace Prefix:	tsha_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-3

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Number of securities into which each warrant or right may be converted. For example, but not limited to, each warrant may be converted into two shares.

+ References

No definition available.

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByEachWarrantOrRight
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-3

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of warrants or rights which entitle the entity to receive future services in exchange for the unvested, forfeitable warrants or rights.

+ References

No definition available.

+ Details

Name:	us-gaap_ClassOfWarrantOrRightUnissued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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

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

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

+ Details

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of expense (income) related to adjustment to fair value of warrant liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 28
-Subparagraph (b)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-28

+ Details

Name:	us-gaap_FairValueAdjustmentOfWarrants
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

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

- Definition

The cash inflow associated with the amount received from entity's raising of capital via private rather than public placement.

+ References

+ Details

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

- Definition

The cash inflow associated with the amount received from holders exercising their stock warrants.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 14
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

+ Details

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

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

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

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

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

- Definition

Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_WarrantsAndRightsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_WarrantsAndRightsOutstandingTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=tsha_TwentyTwentyThreePreFundedWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=tsha_SecuritiesPurchaseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=tsha_SsiWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=tsha_UnderwritingAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=tsha_MayTwentyTwentyFivePreFundedWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=tsha_MayTwentyTwentyFivePreFundedWarrantsOptionOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=tsha_MayTwentyTwentyFivePreFundedWarrantsOptionTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=tsha_JuneTwentyTwentyFourPreFundedWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=tsha_JuneTwentyTwentyFourPreFundedWarrantsOptionOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=tsha_JuneTwentyTwentyFourPreFundedWarrantsOptionTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=tsha_AugustTwoThousandAndTwentyThreePrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=tsha_SsiStrategyHoldingsLlcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Warrants - Additional Information (Details) - USD ($)						1 Months Ended				12 Months Ended
Warrants - Additional Information (Details) - USD ($)	Jun. 06, 2025	May 28, 2025	Jun. 26, 2024	Aug. 16, 2023	Aug. 14, 2023	Dec. 31, 2025	Jun. 30, 2025	Jul. 31, 2024	Apr. 30, 2023	Dec. 31, 2025	Dec. 31, 2024	Apr. 30, 2025
Class of Warrant or Right [Line Items]
Common stock, shares issued						285,051,648				285,051,648	204,943,306
Common stock, par value per share						$ 0.00001				$ 0.00001	$ 0.00001
Warrant liability fair value adjustments										$ 1,199,000	$ (16,000)
Outstanding liability classified warrants						$ 0				0
2023 Pre-Funded Warrants
Class of Warrant or Right [Line Items]
Warrants exercised												9,615,000
Shares of common stock												9,607,145
Securities Purchase Agreement \| 2023 Pre-Funded Warrants
Class of Warrant or Right [Line Items]
Common stock, par value per share					$ 0.001
SSI Warrants
Class of Warrant or Right [Line Items]
Warrant liability fair value adjustments										$ 1,200,000
Warrants exercised						316,667				316,667
Proceeds from exercise of warrants						$ 200,000
SSI Warrants \| Maximum
Class of Warrant or Right [Line Items]
Warrant liability fair value adjustments											$ 100,000
Underwriting Agreement
Class of Warrant or Right [Line Items]
Underwriter agreed to purchase share price of per share		$ 2.585	$ 2.115
Gross proceeds from issuance of common stock	$ 215,600,000
Underwriting Agreement \| May 2025 Pre Funded Warrants
Class of Warrant or Right [Line Items]
Common stock, shares issued		46,868,687
Common stock, par value per share		$ 0.001
Warrants issued		25,858,586
Offering price per share		$ 2.749
Purchase price per share of common stock		2.749
Exercise price of warrants		0.001
Underwriter agreed to purchase share price of per share		$ 2.584
Additional warrants sold upon exercise of underwriters option							0
Beneficial ownership limitation notice period (in days)		61 days
Increase or decrease in beneficial ownership limitation percentage		19.99%
Underwriting Agreement \| May 2025 Pre Funded Warrants Option One
Class of Warrant or Right [Line Items]
Shares beneficially owned		4.99%
Combined voting power beneficially owned		4.99%
Underwriting Agreement \| May 2025 Pre Funded Warrants Option Two
Class of Warrant or Right [Line Items]
Shares beneficially owned		9.99%
Combined voting power beneficially owned		9.99%
Underwriting Agreement \| June 2024 Pre-funded Warrants
Class of Warrant or Right [Line Items]
Common stock, shares issued			14,361,113
Common stock, par value per share			$ 0.001
Warrants issued			18,972,221
Offering price per share			$ 2.249
Exercise price of warrants			0.001
Underwriter agreed to purchase share price of per share			$ 2.114
Additional warrants sold upon exercise of underwriters option								0
Beneficial ownership limitation notice period (in days)			61 days
Increase or decrease in beneficial ownership limitation percentage			19.99%
Underwriting Agreement \| June 2024 Pre-Funded Warrants Option One
Class of Warrant or Right [Line Items]
Shares beneficially owned			4.99%
Combined voting power beneficially owned			4.99%
Underwriting Agreement \| June 2024 Pre-Funded Warrants Option Two
Class of Warrant or Right [Line Items]
Shares beneficially owned			9.99%
Combined voting power beneficially owned			9.99%
Underwriting Agreement \| Common Stock
Class of Warrant or Right [Line Items]
Offering price per share		$ 2.75	$ 2.25
Purchase price per share of common stock		$ 2.75
Private Placement \| Securities Purchase Agreement
Class of Warrant or Right [Line Items]
Beneficial ownership limitation notice period (in days)					61 days
Increase or decrease in beneficial ownership limitation percentage					19.99%
Gross proceeds from issuance of common stock				$ 150,000,000
Net proceeds from issuance of common stock				$ 140,300,000
August 2023 Private Placement \| Securities Purchase Agreement
Class of Warrant or Right [Line Items]
Common stock, shares issued					122,412,376
August 2023 Private Placement \| Securities Purchase Agreement \| 2023 Pre-Funded Warrants
Class of Warrant or Right [Line Items]
Warrants issued					44,250,978
Purchase price per share of common stock					$ 0.9
Exercise price of warrants					$ 0.001
SSI Strategy Holdings LLC \| Private Placement \| Securities Purchase Agreement
Class of Warrant or Right [Line Items]
Common stock, shares issued									705,218
Aggregate gross proceeds									$ 500,000
Warrants issued									525,000
Exercise price of warrants									$ 0.709
Warrants term									10 years