Commitments, Contingencies and Credit Risk (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Commitments Outstanding
Unfunded Commitments Under Lines of Credit	$ 837,450	$ 796,843
Letters of Credit	109,452	124,837
Totals	946,902	921,680
Federal Home Loan Bank Advances
Commitments Outstanding
Outstanding letters of credit	$ 129,600	$ 109,000

The amount of credit risk associated with the commitment to extent the credit.

No definition available.

Name:	bwb_CreditRiskOfCommitmentsToExtendCredit
Namespace Prefix:	bwb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of credit risk associated with the commitment letters of credit.

+ References

No definition available.

+ Details

Name:	bwb_CreditRiskOfLettersOfCredit
Namespace Prefix:	bwb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of credit risk associated with the unfunded commitments under lines of credit.

+ References

No definition available.

+ Details

Name:	bwb_CreditRiskOfUnfundedCommitmentsLinesOfCredit
Namespace Prefix:	bwb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 15
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-15

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477548/944-605-55-12

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_OtherCommitmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_FederalHomeLoanBankAdvancesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: