Document And Entity Information
us-gaap_IncomeLossFromEquityMethodInvestments
Equity in net income of investment
Equity in net (income) of investment
Note To Financial Statement Details Textual
Note 2 - Investments in Real Estate
Note 3 - Assets Measured at Fair Value
Note 4 - Investment in Sentinel Omaha, LLC
Note 2 - Investments in Real Estate - Summary of Investments in Real Estate (Details)
us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Loss from operations
Note 3 - Assets Measured at Fair Value - Fair Value Measurement of Assets (Details)
Net increase in accrued expenses
Note 3 - Assets Measured at Fair Value - Reconciliation of Assets Measured at Fair Value (Details)
us-gaap_RealEstateInvestmentPropertyNet
Total real estate property
Investment in real estate
Note 4 - Investment in Sentinel Omaha, LLC - Balance Sheet (Details)
Note 4 - Investment in Sentinel Omaha, LLC - Statement of Operations (Details)
Equity Components [Axis]
Notes To Financial Statements
Investment in real estate, net
Equity Component [Domain]
Notes To Financial Statements [Abstract]
Accounts Payable and Accrued Liabilities [Member]
us-gaap_RealEstateInvestmentPropertyAtCost
Investment in real estate, at cost
us-gaap_LongTermDebt
Debt
sbp_EquityMethodInvestmentFairValueReservePercent
Equity Method Investment, Fair Value, Reserve, Percent
Represents the percentage of reserve for investments accounted under the equity method.
us-gaap_RealEstateInvestmentPropertyAccumulatedDepreciation
Less - accumulated depreciation
Less: Accumulated depreciation
Net (decrease) increase in accounts payable
Limited partner - 7,753 units
Buildings, furnishings and improvements
Rent and other income
Total revenues
Management fees
sbp_EquityMethodInvestmentFairValueReserve
Balance, Reserve for fair value of investment
Balance, Reserve for fair value of investment
Reserved amount for the fair value portion of investments accounted under the equity method.
Other
Other expenses
Interest income
us-gaap_OperatingExpenses
Total expenses
sbp_NumberOfMultifamilyProperties
Number of Multifamily Properties
Number of multifamily properties held on date.
us-gaap_EquityFairValueDisclosure
Balance
Balance
sbp_NumberOfMarkets
Number of Markets
Represents the number of markets.
Sentinel Omaha LLC [Member]
Information pertaining to the Sentinel Omaha, LLC equity method investment.
Statement of Operations [Member]
Represents information relating to the Statement of Operations.
Balance Sheet [Member]
Represents information relating to the Balance Sheet.
Real estate taxes
Cash and cash equivalents
Depreciation and amortization
Partners' Equity (Deficit):
Investment in Sentinel Omaha, LLC ("Omaha")
Balance, Investment in Sentinel Omaha, LLC
Balance, Investment in Sentinel Omaha, LLC
Balance Sheet Location [Axis]
Balance Sheet Location [Domain]
Amendment Flag
Increase (decrease) in reserve for value of investment
(Increase) decrease in reserve for value of investment
Accounting Policies [Abstract]
Adjustments to reconcile net income to net cash provided by operating activities:
Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block]
Income per unit of limited partnership interest (basic and diluted)
us-gaap_IncreaseDecreaseInOperatingAssets
Net decrease in operating assets
Current Fiscal Year End Date
Document Fiscal Period Focus
Document Fiscal Year Focus
Product and Service [Axis]
Document Period End Date
Product and Service [Domain]
Investment, Name [Domain]
us-gaap_DistributionMadeToLimitedPartnerDistributionsPaidPerUnit
Distribution Made to Limited Partner, Distributions Paid, Per Unit
Entity Emerging Growth Company
Real Estate Disclosure [Text Block]
us-gaap_DistributionMadeToLimitedPartnerDistributionsDeclaredPerUnit
Distribution Made to Limited Partner, Distributions Declared, Per Unit
Document Type
Weighted Average Number of Units of Limited Partnership Interest Outstanding (in shares)
us-gaap_InvestmentOwnedAtCost
Investment Owned, at Cost
Entity Small Business
us-gaap_PolicyTextBlockAbstract
Accounting Policies
Investment, Name [Axis]
Document Information [Line Items]
sbp_RentIncreaseYearlyPercentage
Rent Increase, Yearly, Percentage
The percentage rent increases each year.
Document Information [Table]
us-gaap_AreaOfRealEstateProperty
Description (Square Foot)
Base rental income
Income allocated to limited partners
Entity Filer Category
Debt Instrument [Axis]
Payoff Agreement [Member]
Represents the information pertaining to the Discounted Payoff Agreement ("Payoff Agreement").
Entity Current Reporting Status
Debt Instrument, Name [Domain]
us-gaap_ManagementFeePayable
Management Fee Payable
Income allocated to general partner
Fair Value, Inputs, Level 3 [Member]
us-gaap_NumberOfRealEstateProperties
No. of Prop.
Real Estate Property Ownership [Axis]
Fair Value Hierarchy and NAV [Domain]
Real Estate Properties [Domain]
Schedule of Real Estate Properties [Table Text Block]
Net income (in dollars per share)
us-gaap_EarningsPerShareBasicAndDiluted
Fair Value Hierarchy and NAV [Axis]
Decrease in reserve
The increase (decrease) of the reserve for fair value of investment of assets measured at fair value.
Entity Central Index Key
Depreciation
Entity Registrant Name
Liabilities:
Entity [Domain]
Legal Entity [Axis]
Investment in Sentinel Omaha, LLC, reserve for fair value
Reserve for fair value of investment
Statement [Table]
Statement of Financial Position [Abstract]
us-gaap_Assets
Total assets
Accounts Payable and Accrued Liabilities Disclosure [Text Block]
Cash Flows From Operating Activities:
Statement of Cash Flows [Abstract]
Statement [Line Items]
Entity Common Stock, Shares Outstanding (in shares)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]
Statement of Stockholders' Equity [Abstract]
Income Statement [Abstract]
Revenues:
Cumulative Cash Distributions [Member]
Cumulative distribution of cash made by the entity based on contractual agreements with partnership.
Units of Partnership [Member]
Ownership interest in partnership.
Partner Type of Partners' Capital Account, Name [Domain]
General Partner [Member]
Trading Symbol
Limited Partner [Member]
Real Estate Investment Financial Statements, Disclosure [Table Text Block]
Other assets
Other
Partner Type [Axis]
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]
Net income
Net income
Net increase in net assets
us-gaap_TableTextBlock
Notes Tables
us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations
Cash and cash equivalents and cash in escrow at beginning of period
Cash and cash equivalents and cash in escrow at end of period
Assets:
Equity in net income of investment
Other Assets -
us-gaap_Liabilities
Total liabilities
Other rental income
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Table Text Block]
us-gaap_NetCashProvidedByUsedInOperatingActivities
Net cash provided by operating activites and net change in cash and cash equivalents and cash in escrow
us-gaap_OtherLiabilities
Other liabilities
Net realized gains
Real estate operating expenses
Real estate operating expenses
Tenant security deposit
us-gaap_LiabilitiesAndStockholdersEquity
Total liabilities and partners' equity
Accounts payable
Land
Accrued expenses
us-gaap_PartnersCapitalAccountUnits
Balance (in shares)
Balance (in shares)
Equity Method Investments and Joint Ventures Disclosure [Text Block]
us-gaap_EquityMethodInvestmentOwnershipPercentage
Equity Method Investment, Ownership Percentage
Members equity
Amortization of deferred financing costs
us-gaap_PartnersCapital
Total partners' equity
Balance
Balance
us-gaap_DisclosureTextBlockAbstract
Notes to Financial Statements
us-gaap_Investments
Total investments
Industrial Flex Property [Member]
Information pertaining to industrial flex real estate property investment.
Subsequent Event [Member]
Class of Stock [Axis]
sbp_YearOfAcquisition
Year of Acquisition
Year the property was acquired, in CCYY format.
Investment Advisory, Management and Administrative Service [Member]
Subsequent Event Type [Axis]
Limited partner - units (in shares)
Subsequent Event Type [Domain]
Expenses:
Scenario [Domain]
General partner - 1 unit
Forecast [Member]
General partner - units (in shares)
Subsequent Events [Text Block]
us-gaap_EquityMethodInvestmentDividendsOrDistributions
Proceeds from Equity Method Investment, Distribution
Distribution from investment
Retained Earnings [Member]
Investment in Sentinel Omaha, LLC, net of reserve for fair value of $10,791,509 and $10,709,724 at March 31, 2019 and December 31, 2018, respectively
Total assets
Net unrealized (losses)
Scenario [Axis]