Represents transfers of assets or liabilities between the levels of the fair value hierarchy during the period.

No definition available.

Name:	bhoi_FairValueAssetsAndLiabilitiesAmountOfTransfersBetweenLevelsOfFairValue
Namespace Prefix:	bhoi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_AssetsFairValueDisclosureNonrecurring
Namespace Prefix:	us-gaap_
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

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

- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

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

- Definition

The charge against earnings in the period to reduce the carrying amount of real property to fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=51719941&loc=d3e2921-110230

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

+ Details

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

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=bhoi_NorthpointCentralMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=bhoi_ChasePrivateResidencesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=bhoi_NorthboroughTowerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=bhoi_FriscoSquareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingAndBuildingImprovementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_LandAndLandImprovementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_ChangeDuringPeriodFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ValuationTechniqueAxis=us-gaap_IncomeApproachValuationTechniqueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=bhoi_InvestmentBuildingandBuildingImprovementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Assets and Liabilities Measured at Fair Value (Recurring) (Details) - USD ($)	3 Months Ended			12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Assets and liabilities measured at fair value
Impairment of Real Estate				$ 11,540,000	$ 9,371,000	$ 363,000
Fair Value Assets and Liabilities, Amount of Transfers Between Levels of Fair Value				0	0
Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Impairment of Real Estate				12,300,000
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	$ 0			0
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	2,201,000			2,201,000
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	0			0
Northpoint Central
Assets and liabilities measured at fair value
Impairment of Real Estate		$ 2,700,000		2,700,000
Chase Private Residences [Member]
Assets and liabilities measured at fair value
Impairment of Real Estate	100,000		$ 600,000	700,000
Northborough Tower [Member]
Assets and liabilities measured at fair value
Impairment of Real Estate		2,100,000		2,100,000	9,400,000
Land [Member] \| Frisco Square [Member]
Assets and liabilities measured at fair value
Impairment of Real Estate		$ 6,800,000		6,800,000
Buildings and Improvements \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring					19,397,000
Buildings and Improvements \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring					0
Buildings and Improvements \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	29,500,000			29,500,000	19,397,000
Buildings and Improvements \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring					0
Land and Land Improvements [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	(6,762,000)			(6,762,000)
Land and Land Improvements [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	19,606,000			19,606,000
Changes Measurement [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	(761,000)			(761,000)
Changes Measurement [Member] \| Buildings and Improvements \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	(4,778,000)			(4,778,000)	(9,371,000)
Income Approach Valuation Technique [Member] \| Land and Land Improvements [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	19,606,000			19,606,000
Income Approach Valuation Technique [Member] \| Investment Building and Building Improvements [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Measurements, Nonrecurring [Member]
Assets and liabilities measured at fair value
Assets, Fair Value Disclosure, Nonrecurring	$ 29,500,000			$ 29,500,000	$ 19,397,000