Loans and Allowance for Credit Losses - Summary of Accretable Yield or Income Expected to be Collected (Details) - PCD Loans $ in Thousands	3 Months Ended
Mar. 31, 2026 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance at beginning of year	$ 0
New loans acquired from Keystone Bank, SSB acquisition	708
Accretion of income	(8)
Balance at end of period	$ 700

Financing receivable, purchased with credit deterioration, accretable yield.

No definition available.

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

- Definition

Financing receivable, purchased with credit deterioration, accretable yield, accretion.

+ References

No definition available.

+ Details

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

- Definition

Financing receivable, purchased with credit deterioration, accretable yield, additions.

+ References

No definition available.

+ Details

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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

- Details

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Namespace Prefix:
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Balance Type:
Period Type: