Fair Value Measurement - Recurring (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	$ 768,247	$ 604,104
Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Total Fair Value of Financial Assets	811,402	636,693
Total Fair Value of Financial Liabilities	8,210	8,601
Fair Value Swaps \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Fair Value Swap Derivatives	10,487
Interest Rate Caps \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Interest Rate Derivatives	19,319	18,717
Interest Rate Swaps \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Interest Rate Derivatives	13,349	13,872
Interest Rate Swaps	8,210	8,601
U.S. Treasury Securities
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	167,748
U.S. Treasury Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	167,748
Municipal Bonds
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	122,265	132,524
Municipal Bonds \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	122,265	132,524
Mortgage-Backed Securities
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	244,890	235,315
Mortgage-Backed Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	244,890	235,315
Corporate Securities
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	134,186	130,605
Corporate Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	134,186	130,605
U.S Government Agency Securities
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	22,082
SBA Securities
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value		18,674
SBA Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	22,082	18,674
Asset-Backed Securities
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	77,076	86,986
Asset-Backed Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	77,076	86,986
Level 1
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	167,748
Level 1 \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Total Fair Value of Financial Assets	167,748
Level 1 \| U.S. Treasury Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	167,748
Level 2
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	600,499	604,104
Level 2 \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Total Fair Value of Financial Assets	643,654	636,693
Total Fair Value of Financial Liabilities	8,210	8,601
Level 2 \| Fair Value Swaps
Balances of the assets and liabilities measured at fair value on a recurring basis
Fair Value Swap Derivatives	10,487
Level 2 \| Fair Value Swaps \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Fair Value Swap Derivatives	10,487
Level 2 \| Interest Rate Caps
Balances of the assets and liabilities measured at fair value on a recurring basis
Interest Rate Derivatives	19,319	18,717
Level 2 \| Interest Rate Caps \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Interest Rate Derivatives	19,319	18,717
Level 2 \| Interest Rate Swaps
Balances of the assets and liabilities measured at fair value on a recurring basis
Interest Rate Derivatives	13,349	13,872
Interest Rate Swaps	8,210	8,601
Level 2 \| Interest Rate Swaps \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Interest Rate Derivatives	13,349	13,872
Interest Rate Swaps	8,210	8,601
Level 2 \| Municipal Bonds \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	122,265	132,524
Level 2 \| Mortgage-Backed Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	244,890	235,315
Level 2 \| Corporate Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	134,186	130,605
Level 2 \| SBA Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	22,082	18,674
Level 2 \| Asset-Backed Securities \| Recurring
Balances of the assets and liabilities measured at fair value on a recurring basis
Securities Available for Sale, at Fair Value	$ 77,076	$ 86,986

Fair value portion of asset recognized for present right to economic benefit.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

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

- Definition

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479130/326-30-45-1

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

+ References

No definition available.

+ Details

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

- Definition

Fair value as of the balance sheet date of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities.

+ References

No definition available.

+ Details

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

- Definition

Fair value of financial and nonfinancial obligations.

+ References

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

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

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

- Definition

Fair value as of the balance sheet date of price risk derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets on the balance sheet.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_EquitySwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateCapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=bwb_SmallBusinessAdministrationSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: