Loans And Allowance For Loan Losses (Troubled Debt Restructurings) (Details)	12 Months Ended
Dec. 31, 2015 USD ($) loan	Dec. 31, 2014 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	15	3
Pre-Modification Outstanding Recorded Investment	$ 723,112	$ 697,515
Post-Modification Outstanding Recorded Investment	$ 723,112	$ 697,515
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	3	1
Pre-Modification Outstanding Recorded Investment	$ 101,772	$ 85,397
Post-Modification Outstanding Recorded Investment	$ 101,772	$ 85,397
Residential Real Estate - Investor [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	10
Pre-Modification Outstanding Recorded Investment	$ 370,210
Post-Modification Outstanding Recorded Investment	$ 370,210
Residential Real Estate - Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	1	2
Pre-Modification Outstanding Recorded Investment	$ 122,097	$ 612,118
Post-Modification Outstanding Recorded Investment	$ 122,097	$ 612,118
Home Equity Line Of Credit [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| loan	1
Pre-Modification Outstanding Recorded Investment	$ 129,033
Post-Modification Outstanding Recorded Investment	$ 129,033

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.

No definition available.

+ Details

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

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bybk_CommercialAndIndustrialLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bybk_ResidentialRealEstateInvestorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=bybk_ResidentialRealEstateOwnerOccupiedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: