Debt Instrument, Full Or Partial Repayment Date

No definition available.

Name:	botj_DebtInstrumentFullOrPartialRepaymentDate
Namespace Prefix:	botj_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Principal Notes Sold, Value

+ References

No definition available.

+ Details

Name:	botj_PrincipalNotesSoldValue
Namespace Prefix:	botj_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow associated with the proceeds from sale of notes receivable, as well as principal collections from a borrowing supported by a written promise to pay an obligation (note receivable).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

+ Details

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

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=botj_TwentyTwentyOfferingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=botj_CapitalNotesFourPercentDueJanuaryTwentyFourTwoThousandTwentyTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Narrative) (Details) - USD ($)			6 Months Ended
Subsequent Events (Narrative) (Details) - USD ($)	Jul. 08, 2020	Jun. 24, 2020	Jun. 30, 2020	Apr. 13, 2020
Subsequent Event [Line Items]
Proceeds used to pay off debt			$ 5,000,000
2020 Offering [Member]
Subsequent Event [Line Items]
Principal notes				$ 10,050,000
Proceeds from unregistered debt securities			$ 7,275,000
Debt Instrument, Maturity Date			Jun. 30, 2025
Full or partial payment date			Jun. 30, 2021
Subsequent Event [Member] \| 2020 Offering [Member]
Subsequent Event [Line Items]
Proceeds from unregistered debt securities	$ 2,775,000
Debt instrument, interest rate, stated percentage	3.25%
Capital notes, interest rate	3.25%
Capital Notes 4% Due 1/24/2022 [Member]
Subsequent Event [Line Items]
Debt instrument, interest rate, stated percentage			4.00%
Proceeds used to pay off debt		$ 5,000,000
Capital notes, interest rate			4.00%