Financing receivable allowance for credit losses related to purchased credit impaired loans.

No definition available.

Name:	bayk_FinancingReceivableAllowanceForCreditLossesRelatedToPurchasedCreditImpairedLoans
Namespace Prefix:	bayk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Financing receivable, purchased credit impaired loans.

+ References

No definition available.

+ Details

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Namespace Prefix:	bayk_
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

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Period Type:	duration

- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(7)(2))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121599878&loc=SL82895884-210446

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 13
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=121599337&loc=SL82919249-210447

+ Details

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

- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

+ Details

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

- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

+ Details

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

- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

+ Details

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

- Definition

The balance of financing receivables that were individually evaluated for impairment.

+ References

+ Details

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

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121593590&loc=d3e4428-111522

+ Details

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

- Details

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- Details

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- Details

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Allowance for Loan Losses - Loans Evaluated for Impairment Individually and Collectively by Loan Type (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	$ 2,887		$ 1,039
Loans collectively evaluated for impairment	10,012		6,523
Purchased credit-impaired loans	0		0
Total allowance for loan losses	12,899	$ 12,007	7,562	$ 7,495	$ 7,479	$ 7,902
Loans individually evaluated for impairment	18,108		6,069
Loans collectively evaluated for impairment	1,034,435		913,564
Purchased credit-impaired loans	4,190		4,870
Total Loans	1,056,733		924,503
Mortgage Loans on Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	2,036		878
Loans collectively evaluated for impairment	7,551		4,494
Purchased credit-impaired loans	0		0
Total allowance for loan losses	9,587	8,863	5,372	5,081	5,052	4,967
Loans individually evaluated for impairment	12,249		5,502
Loans collectively evaluated for impairment	789,881		720,458
Purchased credit-impaired loans	4,153		4,828
Total Loans	806,283		730,788
Commercial and Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	746		49
Loans collectively evaluated for impairment	2,143		1,522
Purchased credit-impaired loans	0		0
Total allowance for loan losses	2,889		1,571
Loans individually evaluated for impairment	5,754		455
Loans collectively evaluated for impairment	238,253		181,275
Total Loans	244,007		181,730
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans individually evaluated for impairment	105		112
Loans collectively evaluated for impairment	318		507
Purchased credit-impaired loans	0		0
Total allowance for loan losses	423	$ 518	619	$ 762	$ 890	$ 1,561
Loans individually evaluated for impairment	105		112
Loans collectively evaluated for impairment	6,301		11,831
Purchased credit-impaired loans	37		42
Total Loans	$ 6,443		$ 11,985