Financing receivable accrued interest for nonaccrual loans.

No definition available.

Name:	tcbx_FinancingReceivableAccruedInterestForNonaccrualLoans
Namespace Prefix:	tcbx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Financing receivable from securitization.

+ References

No definition available.

+ Details

Name:	tcbx_FinancingReceivableFromSecuritization
Namespace Prefix:	tcbx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

No definition available.

+ Details

Name:	tcbx_FinancingReceivableNumberOfContractsModified
Namespace Prefix:	tcbx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Loans and leases receivable unaccreted discounts and deferred fees net of deferred costs.

+ References

No definition available.

+ Details

Name:	tcbx_LoansAndLeasesReceivableUnaccretedDiscountsAndDeferredFeesNetOfDeferredCosts
Namespace Prefix:	tcbx_
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/2009/role/commonPracticeRef
-Topic 310
-SubTopic 20
-Name Accounting Standards Codification
-Section 40
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481628/310-20-40-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

+ Details

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

- Definition

Amortized cost of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-34

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 44
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-44

+ Details

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

- Details

Name:	srt_MortgageLoansOnRealEstateLoanTypeAxis=tcbx_AprilMortgageLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateLoanTypeAxis=tcbx_JuneMortgageLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Loans and Allowance for Credit Losses - Additional Information (Details)	9 Months Ended		12 Months Ended
	Sep. 30, 2025 USD ($) Loan	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($) Loan	Jun. 30, 2025 USD ($)	Jun. 03, 2025 USD ($)	Apr. 01, 2025 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans unaccreted discounts and deferred fees net of deferred costs	$ 21,600,000		$ 16,600,000
Non-accrual loans, accrued interest	$ 725,000	$ 1,300,000
Number of loans \| Loan	1		0
Restructured loans subsequent payment default	$ 0		$ 0
Securitized loan transactions				$ 250,000,000	$ 150,000,000	$ 100,000,000
April Mortgage Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Securitized loan transactions						$ 100,000,000
June Mortgage Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Securitized loan transactions					$ 150,000,000