Loans and Allowance for Credit Losses - Schedule of Amortized Cost and Unpaid Principal for Impaired Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	$ 4,371,528	$ 4,120,291
Unpaid Principal	4,383,979	4,136,981
Difference	(12,451)	(16,690)
Allowance for credit losses	(34,815)	(42,807)
Loans, net	4,336,713	4,077,484
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	817,064	678,144
Unpaid Principal	818,140	679,239
Difference	(1,076)	(1,095)
Construction, land development, land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	131,862	90,976
Unpaid Principal	132,413	91,147
Difference	(551)	(171)
1-4 family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	129,588	125,981
Unpaid Principal	129,768	126,185
Difference	(180)	(204)
Farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	62,698	68,934
Unpaid Principal	62,871	69,185
Difference	(173)	(251)
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	1,251,939	1,251,110
Unpaid Principal	1,258,981	1,262,493
Difference	(7,042)	(11,383)
Factored receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	1,213,702	1,237,449
Unpaid Principal	1,217,129	1,241,032
Difference	(3,427)	(3,583)
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	8,166	8,868
Unpaid Principal	8,168	8,871
Difference	(2)	(3)
Mortgage warehouse
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized Cost	756,509	658,829
Unpaid Principal	756,509	658,829
Difference	$ 0	$ 0

Financing Receivable, Investment Net Of Unpaid Principal, Excluding Accrued Interest

No definition available.

Name:	tbk_FinancingReceivableInvestmentNetOfUnpaidPrincipalExcludingAccruedInterest
Namespace Prefix:	tbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Financing Receivable, Unpaid Principal, Excluding Accrued Interest

+ References

No definition available.

+ Details

Name:	tbk_FinancingReceivableUnpaidPrincipalExcludingAccruedInterest
Namespace Prefix:	tbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease.

+ References

+ Details

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

- Definition

Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479319/326-20-50-5

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialRealEstatePortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=tbk_ConstructionLandDevelopmentLandPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=tbk_FarmlandPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=tbk_FactoredReceivablesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=tbk_MortgageWarehouseSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: