Securities & Allowance for Securities Credit Losses - Narrative (Details)	12 Months Ended
Dec. 31, 2024 USD ($) position bond security	Dec. 31, 2023 USD ($) bond position	Dec. 31, 2022 USD ($)
Schedule of Available-for-sale and Held-to-Maturity Securities [Line Items]
Securities	$ 0	$ 0
Proceeds from debt securities, available-for-sale	187,614,000	50,750,000
Proceeds from sales, calls, maturities and paydowns	7,351,000	$ 3,216,000
Charge off	$ 210,000
Number of HTM bonds \| bond	2	1
Available-for-sale, number of positions \| position	776
Held to maturity number of positions \| position		880
Available sale of securities, percentage of impairment in amortized cost basis	4.30%
Held to maturity securities, percentage of impairment in amortized cost basis		6.00%
Allowance for credit loss	$ 0	$ 0	$ 0
Debt securities, held to maturity non-accrual	0
Equity securities, gain (loss)	$ (5,000)	7,000
U.S. government and federal agencies
Schedule of Available-for-sale and Held-to-Maturity Securities [Line Items]
Available-for-sale, number of positions \| position	37
Available-for-sale, number of securities \| security	49
Allowance for credit loss	$ 0	0	0
Mortgage-backed securities
Schedule of Available-for-sale and Held-to-Maturity Securities [Line Items]
Available-for-sale, number of positions \| position	14
Available-for-sale, number of securities \| security	19
Allowance for credit loss	$ 0	0
Corporate Bonds
Schedule of Available-for-sale and Held-to-Maturity Securities [Line Items]
Available-for-sale, number of positions \| position	76
Available-for-sale, number of securities \| security	90
Allowance for credit loss	$ 0	0	0
State and municipal securities
Schedule of Available-for-sale and Held-to-Maturity Securities [Line Items]
Available-for-sale, number of positions \| position	269
Available-for-sale, number of securities \| security	298
Allowance for credit loss	$ 0	$ 0	$ 0

Available-for-Sale Securities, Unrealized Loss Position, Aggregate Impairment, Percentage

No definition available.

Name:	chnbrdg_AvailableForSaleSecuritiesUnrealizedLossPositionAggregateImpairmentPercentage
Namespace Prefix:	chnbrdg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Securities, Available For Sale, Number Of Securities

+ References

No definition available.

+ Details

Name:	chnbrdg_DebtSecuritiesAvailableForSaleNumberOfSecurities
Namespace Prefix:	chnbrdg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Securities, Held-To-Maturity, Unrealized Loss Position, Number Of Positions

+ References

No definition available.

+ Details

Name:	chnbrdg_DebtSecuritiesHeldToMaturityUnrealizedLossPositionNumberOfPositions
Namespace Prefix:	chnbrdg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Held-To-Maturity Securities, Unrealized Loss Position, Aggregate Impairment, Percentage

+ References

No definition available.

+ Details

Name:	chnbrdg_HeldToMaturitySecuritiesUnrealizedLossPositionAggregateImpairmentPercentage
Namespace Prefix:	chnbrdg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of Held-to-Maturity Bonds

+ References

No definition available.

+ Details

Name:	chnbrdg_NumberOfHeldToMaturityBonds
Namespace Prefix:	chnbrdg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Schedule of Available-for-sale and Held-to-Maturity Securities

+ References

No definition available.

+ Details

Name:	chnbrdg_ScheduleOfAvailableForSaleAndHeldToMaturitySecuritiesLineItems
Namespace Prefix:	chnbrdg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount excluding accrued interest, of allowance for credit loss on 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/2003/role/disclosureRef
-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_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-6

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479106/326-30-50-4

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount excluding accrued interest, of investment in debt security measured at amortized cost (held-to-maturity) on nonaccrual status.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

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

- Definition

Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(d)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 321
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479536/321-10-50-4

+ Details

Name:	us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash inflow from recovery of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), previously written off.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

+ Details

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

- Definition

Amount of cash inflow from maturity, prepayment and call 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 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481830/320-10-45-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 11
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

+ Details

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

- Definition

The cash inflow associated with the maturity, prepayments and calls (requests for early payments) of debt securities designated as held-to-maturity.

+ References

+ Details

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

- Definition

Fair value of the securities pledged as collateral against securities loaned.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483444/210-20-55-12

+ Details

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

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateBondSecuritiesMember
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: