XML 75 R60.htm IDEA: XBRL DOCUMENT
v3.21.1

Note 10 - Income Tax Benefit (Details Textual) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2018
Domestic Tax Authority [Member] |  |
Operating Loss Carryforwards, Total | $ 25.0 | $ 10.8
Reduction of Operating Loss Carryforward, Tax Audit | $ 1.3 |
Open Tax Year | 2017 2018 2019 2020 |
State and Local Jurisdiction [Member] |  |
Operating Loss Carryforwards, Total | $ 30.0 |
Open Tax Year | 2017 2018 2019 2020 |

X
- Definition The amount of reduction in operating loss carryforward due to completion of tax audit. + References No definition available. + Details
Name: | bomn_ReductionOfOperatingLossCarryforwardTaxAudit
Namespace Prefix: | bomn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Tax year that remains open to examination under enacted tax laws, in CCYY format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
Name: | us-gaap_OpenTaxYear
Namespace Prefix: | us-gaap_
Data Type: | us-types:gYearListItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_DomesticCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |