XML 89 R22.htm IDEA: XBRL DOCUMENT
v3.20.1

Note 16 - Custodial Risk | 12 Months Ended
--- | ---
Dec. 31, 2019
Notes to Financial Statements |
Custodial Risk Disclosure [Text Block] |
NOTE 16 . | CUSTODIAL RISK
As of December 31, 2019 , we had approximately $15,610,000 in excess of federally insured limits on deposit with financial institutions.

X
- Definition A complete disclosure of custodial risk. + References No definition available. + Details
Name: | bomn_CustodialRiskDisclosureTextBlock
Namespace Prefix: | bomn_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_DisclosureTextBlockAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration