Note 1 - Organization and Background (Details Textual) - USD ($)	Jun. 30, 2026	May 18, 2026
CopperPoint Insurance Company [Member] \| Indemnification Agreement [Member]
Gain Contingency, Unrecorded Amount	$ 5,250,000
Discontinued Operations, Held-for-Sale [Member] \| GIG [Member]
Disposal Group, Including Discontinued Operation, Consideration		$ 84,300,000
Disposal Group, Including Discontinued Operation, Consideration, Percentage of Proceeds		93.00%

Represents the percentage of consideration proceeds that will go to the company.

No definition available.

Name:	boc_DisposalGroupIncludingDiscontinuedOperationConsiderationPercentageOfProceeds
Namespace Prefix:	boc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 360
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482099/360-10-50-3

+ Details

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

- Definition

The amount or range of possible amounts of gain that could be realized upon the resolution of a contingency.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 450
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483049/450-30-50-1

+ Details

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

- Details

Name:	dei_LegalEntityAxis=boc_CopperpointInsuranceCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GainContingenciesByNatureAxis=us-gaap_IndemnificationGuaranteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsHeldforsaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleByTypeAxis=boc_GIGMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: