Note 2 - Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2021
Notes to Financial Statements
Significant Accounting Policies [Text Block]	NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Consolidation Policy The financial statements of Boston Omaha Corporation include the accounts of the Company and our consolidated subsidiaries, which are comprised of voting interest entities in which we have a controlling financial interest and variable interest entities in which we are the primary beneficiary in accordance with ASC 810, Consolidation. The equity attributable to non-controlling interests in subsidiaries is shown separately in the accompanying consolidated balance sheets. Our consolidated subsidiaries include: Link Media Holdings, LLC which we refer to as “LMH” Link Media Alabama, LLC which we refer to as “LMA” Link Media Florida, LLC which we refer to as “LMF” Link Media Wisconsin, LLC which we refer to as “LMW” Link Media Georgia, LLC which we refer to as “LMG” Link Media Midwest, LLC which we refer to as “LMM” Link Media Omaha, LLC which we refer to as “LMO” Link Media Properties, LLC which we refer to as “LMP” Link Media Southeast, LLC which we refer to as “LMSE” Link Media Services, LLC which we refer to as “LMS” General Indemnity Group, LLC which we refer to as “GIG” The Warnock Agency, Inc. which we refer to as “Warnock” United Casualty and Surety Insurance Company which we refer to as “UCS” Surety Support Services, Inc. which we refer to as “SSS” South Coast Surety Insurance Services, LLC which we refer to as “SCS” Boston Omaha Investments, LLC which we refer to as “BOIC” Boston Omaha Asset Management, LLC which we refer to as “BOAM” BOAM BFR LLC which we refer to as "BOAM BFR" BOC DFH, LLC which we refer to as “BOC DFH” BOC OPS LLC which we refer to as "BOC OPS" BOC Yellowstone which we refer to as "BOC Yellowstone" BOC Yellowstone II LLC which we refer to as “BOC Yellowstone II” Fiber is Fast, LLC which we refer to as "FIF" FIF AireBeam LLC, which we refer to as “AireBeam” FIF Utah LLC, which we refer to as “FIF Utah” Yellowstone Acquisition Company, which we refer to as "Yellowstone" Revenues The majority of our advertising revenues are derived from contracts for advertising space on billboard structures and are accounted for under Financial Accounting Standards Board, which we refer to as the “FASB,” Accounting Standards Codification, which we refer to as “ASC,” 606, Revenue from Contracts with Customers. Premium revenues derived from our insurance operations are subject to ASC 944, Financial Services – Insurance. Revenue Recognition Billboard Rentals We generate revenue from outdoor advertising through the leasing of advertising space on billboards. The terms of the contracts range from less than one month to three years and are generally billed monthly. Revenue for advertising space rental is recognized on a straight-line basis over the term of the contract. Advertising revenue is reported net of agency commissions. Agency commissions are calculated based on a stated percentage applied to gross billing revenue for operations. Payments received in advance of being earned are recorded as deferred revenue. Another component of billboard rentals consists of production services which include creating and printing advertising copy. Contract revenues for production services are accounted for under ASC 606, Revenue from Contracts with Customers. Revenues are recognized at a point in time upon satisfaction of the contract, which is typically less than one week. Deferred Revenues We record deferred revenues when cash payments are received in advance of being earned or when we have an unconditional right to consideration before satisfying our performance obligation. The term between invoicing and when a payment is due is not significant. For certain services we require payment before the product or services are delivered to the customer. The balance of deferred revenue is considered short-term and will be recognized in revenue within twelve months. Premiums and Unearned Premium Reserves Premiums written are recognized as revenues based on a pro-rata daily calculation over the respective terms of the policies in-force. The cost of reinsurance ceded is initially written as prepaid reinsurance premiums and is amortized over the reinsurance contract period in proportion to the amount of insurance protection provided. Premiums ceded of $152,255 and $100,114 for the three months ended March 31, 2021 and 2020, respectively, are included within “Premiums earned” in our consolidated statements of operations. Commissions We generate revenue from commissions on surety bond sales and account for commissions under ASC 606. Insurance commissions are earned from various insurance companies based upon our agency agreements with them. We arrange with various insurance companies for the provision of a surety bond for entities that require a surety bond. The insurance company sets the price of the bond. The contract with the insurance company is fulfilled when the bond is issued by the insurance agency on behalf of the insurance company. The insurance commissions are calculated based upon a stated percentage applied to the gross premiums on bonds. Commissions are recognized at a point in time, on a bond-by-bond basis as of the policy effective date and are generally nonrefundable. Broadband Revenues Broadband revenue is derived principally from internet services and is recognized on a straight-line basis over the term of the contract in the period the services are rendered. Revenue received or receivable in advance of the delivery of services is included in deferred revenue. Loss and Loss Adjustment Expenses Unpaid losses and loss adjustment expenses represent estimates for the ultimate cost of unpaid reported and unreported claims incurred and related expenses. Estimates for losses and loss adjustment expenses are based on past experience of investigating and adjusting claims and consideration of the level of premiums written during the current and prior year. Since the reserves are based on estimates, the ultimate liability may differ from the estimated reserve. The effects of changes in estimated reserves are included within cost of insurance revenues in our results of operations in the period in which the estimates are updated. The reserves are included within accounts payable and accrued expenses in our consolidated balance sheets. Variable Interest Entities (VIEs) We determine whether an entity is a VIE and, if so, whether it should be consolidated by utilizing judgments and estimates that are inherently subjective. Our determination of whether an entity in which we hold a direct or indirect variable interest is a VIE is based on several factors, including whether the entity’s total equity investment at risk upon inception is sufficient to finance the entity’s activities without additional subordinated financial support. We make judgments regarding the sufficiency of the equity at risk based first on a qualitative analysis, and then a quantitative analysis, if necessary. We analyze any investments in VIEs to determine if we are the primary beneficiary. In evaluating whether we are the primary beneficiary, we evaluate our direct and indirect economic interests in the entity. A reporting entity is determined to be the primary beneficiary if it holds a controlling financial interest in the VIE. Determining which reporting entity, if any, has a controlling financial interest in a VIE is primarily a qualitative approach focused on identifying which reporting entity has both: (i) the power to direct the activities of a VIE that most significantly impact such entity’s economic performance; and (ii) the obligation to absorb losses or the right to receive benefits from such entity that could potentially be significant to such entity. Performance of that analysis requires the exercise of judgment. We consider a variety of factors in identifying the entity that holds the power to direct matters that most significantly impact the VIE’s economic performance including, but not limited to, the ability to direct operating decisions and activities. In addition, we consider the rights of other investors to participate in those decisions. We determine whether we are the primary beneficiary of a VIE at the time we become involved with a variable interest entity and reconsider that conclusion continually. We consolidate any VIE of which we are the primary beneficiary. Income Taxes We compute our year-to-date provision for income taxes by applying the estimated annual effective tax rate to year-to-date pre-tax income or loss and adjust the provision for discrete tax items recorded in the period. Class A Common Stock Subject to Possible Redemption As discussed in Note 18, all of the 13,598,898 Class A Common Stock sold as part of the Units in Yellowstone's Public Offering contain a redemption feature which allows for the redemption of such public shares in connection with the Yellowstone's liquidation, if there is a stockholder vote or tender offer in connection with the Business Combination and in connection with certain amendments to Yellowstone's second amended and restated certificate of incorporation. In accordance with SEC and its staff’s guidance on redeemable equity instruments, which has been codified in ASC 480-10-S99, redemption provisions not solely within the control of the Company require common stock subject to redemption to be classified outside of permanent equity. Ordinary liquidation events, which involve the redemption and liquidation of all of the entity’s equity instruments, are excluded from the provisions of ASC 480. Yellowstone recognizes changes in redemption value immediately as they occur and adjusts the carrying value of redeemable common stock to equal the redemption value at the end of each reporting period. Increases or decreases in the carrying amount of redeemable common stock are affected by charges against additional paid in capital and accumulated deficit. Yellowstone's Common A Common Stock subject to redemption is included within "Redeemable Noncontrolling Interest" within our consolidated Balance Sheets. Warrants Liability We account for warrants for shares of Yellowstone's common stock that are not indexed to Yellowstone's own stock as liabilities at fair value on the balance sheet. The warrants are subject to remeasurement at each balance sheet date and any change in fair value is recognized in our statement of operations. For issued or modified warrants that meet all of the criteria for equity classification, the warrants are required to be recorded as a component of additional paid-in capital at the time of issuance. For issued or modified warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded as a liability at their initial fair value on the date of issuance, and each balance sheet date thereafter. Changes in the estimated fair value of the warrants are recognized as a non-cash gain or loss on the statements of operations. The fair value of the Public Warrants issued in connection with Yellowstone's Public Offering has been measured based on the listed market price of such Warrants (see Note 9).

Note 2 - Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2021

Significant Accounting Policies [Text Block]

NOTE 2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Consolidation Policy

The financial statements of Boston Omaha Corporation include the accounts of the Company and our consolidated subsidiaries, which are comprised of voting interest entities in which we have a controlling financial interest and variable interest entities in which we are the primary beneficiary in accordance with ASC 810, Consolidation. The equity attributable to non-controlling interests in subsidiaries is shown separately in the accompanying consolidated balance sheets.

Our consolidated subsidiaries include:

Link Media Holdings, LLC which we refer to as “LMH”

Link Media Alabama, LLC which we refer to as “LMA”

Link Media Florida, LLC which we refer to as “LMF”

Link Media Wisconsin, LLC which we refer to as “LMW”

Link Media Georgia, LLC which we refer to as “LMG”

Link Media Midwest, LLC which we refer to as “LMM”

Link Media Omaha, LLC which we refer to as “LMO”

Link Media Properties, LLC which we refer to as “LMP”

Link Media Southeast, LLC which we refer to as “LMSE”

Link Media Services, LLC which we refer to as “LMS”

General Indemnity Group, LLC which we refer to as “GIG”

The Warnock Agency, Inc. which we refer to as “Warnock”

United Casualty and Surety Insurance Company which we refer to as “UCS”

Surety Support Services, Inc. which we refer to as “SSS”

South Coast Surety Insurance Services, LLC which we refer to as “SCS”

Boston Omaha Investments, LLC which we refer to as “BOIC”

Boston Omaha Asset Management, LLC which we refer to as “BOAM”

BOAM BFR LLC which we refer to as "BOAM BFR"

BOC DFH, LLC which we refer to as “BOC DFH”

BOC OPS LLC which we refer to as "BOC OPS"

BOC Yellowstone which we refer to as "BOC Yellowstone"

BOC Yellowstone II LLC which we refer to as “BOC Yellowstone II”

Fiber is Fast, LLC which we refer to as "FIF"

FIF AireBeam LLC, which we refer to as “AireBeam”

FIF Utah LLC, which we refer to as “FIF Utah”

Yellowstone Acquisition Company, which we refer to as "Yellowstone"

Revenues

The majority of our advertising revenues are derived from contracts for advertising space on billboard structures and are accounted for under Financial Accounting Standards Board, which we refer to as the “FASB,” Accounting Standards Codification, which we refer to as “ASC,” 606, Revenue from Contracts with Customers.

Premium revenues derived from our insurance operations are subject to ASC 944, Financial Services – Insurance.

Revenue Recognition

Billboard Rentals

We generate revenue from outdoor advertising through the leasing of advertising space on billboards. The terms of the contracts range from less than one month to three years and are generally billed monthly. Revenue for advertising space rental is recognized on a straight-line basis over the term of the contract. Advertising revenue is reported net of agency commissions. Agency commissions are calculated based on a stated percentage applied to gross billing revenue for operations. Payments received in advance of being earned are recorded as deferred revenue.

Another component of billboard rentals consists of production services which include creating and printing advertising copy. Contract revenues for production services are accounted for under ASC 606, Revenue from Contracts with Customers. Revenues are recognized at a point in time upon satisfaction of the contract, which is typically less than one week.

Deferred Revenues

We record deferred revenues when cash payments are received in advance of being earned or when we have an unconditional right to consideration before satisfying our performance obligation. The term between invoicing and when a payment is due is not significant. For certain services we require payment before the product or services are delivered to the customer. The balance of deferred revenue is considered short-term and will be recognized in revenue within twelve months.

Premiums and Unearned Premium Reserves

Premiums written are recognized as revenues based on a pro-rata daily calculation over the respective terms of the policies in-force. The cost of reinsurance ceded is initially written as prepaid reinsurance premiums and is amortized over the reinsurance contract period in proportion to the amount of insurance protection provided. Premiums ceded of $152,255 and $100,114 for the three months ended March 31, 2021 and 2020, respectively, are included within “Premiums earned” in our consolidated statements of operations.

Commissions

We generate revenue from commissions on surety bond sales and account for commissions under ASC 606. Insurance commissions are earned from various insurance companies based upon our agency agreements with them. We arrange with various insurance companies for the provision of a surety bond for entities that require a surety bond. The insurance company sets the price of the bond. The contract with the insurance company is fulfilled when the bond is issued by the insurance agency on behalf of the insurance company. The insurance commissions are calculated based upon a stated percentage applied to the gross premiums on bonds. Commissions are recognized at a point in time, on a bond-by-bond basis as of the policy effective date and are generally nonrefundable.

Broadband Revenues

Broadband revenue is derived principally from internet services and is recognized on a straight-line basis over the term of the contract in the period the services are rendered. Revenue received or receivable in advance of the delivery of services is included in deferred revenue.

Loss and Loss Adjustment Expenses

Unpaid losses and loss adjustment expenses represent estimates for the ultimate cost of unpaid reported and unreported claims incurred and related expenses. Estimates for losses and loss adjustment expenses are based on past experience of investigating and adjusting claims and consideration of the level of premiums written during the current and prior year. Since the reserves are based on estimates, the ultimate liability may differ from the estimated reserve. The effects of changes in estimated reserves are included within cost of insurance revenues in our results of operations in the period in which the estimates are updated. The reserves are included within accounts payable and accrued expenses in our consolidated balance sheets.

Variable Interest Entities (VIEs)

We determine whether an entity is a VIE and, if so, whether it should be consolidated by utilizing judgments and estimates that are inherently subjective. Our determination of whether an entity in which we hold a direct or indirect variable interest is a VIE is based on several factors, including whether the entity’s total equity investment at risk upon inception is sufficient to finance the entity’s activities without additional subordinated financial support. We make judgments regarding the sufficiency of the equity at risk based first on a qualitative analysis, and then a quantitative analysis, if necessary.

We analyze any investments in VIEs to determine if we are the primary beneficiary. In evaluating whether we are the primary beneficiary, we evaluate our direct and indirect economic interests in the entity. A reporting entity is determined to be the primary beneficiary if it holds a controlling financial interest in the VIE. Determining which reporting entity, if any, has a controlling financial interest in a VIE is primarily a qualitative approach focused on identifying which reporting entity has both: (i) the power to direct the activities of a VIE that most significantly impact such entity’s economic performance; and (ii) the obligation to absorb losses or the right to receive benefits from such entity that could potentially be significant to such entity. Performance of that analysis requires the exercise of judgment.

We consider a variety of factors in identifying the entity that holds the power to direct matters that most significantly impact the VIE’s economic performance including, but not limited to, the ability to direct operating decisions and activities. In addition, we consider the rights of other investors to participate in those decisions. We determine whether we are the primary beneficiary of a VIE at the time we become involved with a variable interest entity and reconsider that conclusion continually. We consolidate any VIE of which we are the primary beneficiary.

Income Taxes

We compute our year-to-date provision for income taxes by applying the estimated annual effective tax rate to year-to-date pre-tax income or loss and adjust the provision for discrete tax items recorded in the period.

Class A Common Stock Subject to Possible Redemption

As discussed in Note 18, all of the 13,598,898 Class A Common Stock sold as part of the Units in Yellowstone's Public Offering contain a redemption feature which allows for the redemption of such public shares in connection with the Yellowstone's liquidation, if there is a stockholder vote or tender offer in connection with the Business Combination and in connection with certain amendments to Yellowstone's second amended and restated certificate of incorporation. In accordance with SEC and its staff’s guidance on redeemable equity instruments, which has been codified in ASC 480-10-S99, redemption provisions not solely within the control of the Company require common stock subject to redemption to be classified outside of permanent equity. Ordinary liquidation events, which involve the redemption and liquidation of all of the entity’s equity instruments, are excluded from the provisions of ASC 480.

Yellowstone recognizes changes in redemption value immediately as they occur and adjusts the carrying value of redeemable common stock to equal the redemption value at the end of each reporting period. Increases or decreases in the carrying amount of redeemable common stock are affected by charges against additional paid in capital and accumulated deficit. Yellowstone's Common A Common Stock subject to redemption is included within "Redeemable Noncontrolling Interest" within our consolidated Balance Sheets.

Warrants Liability

We account for warrants for shares of Yellowstone's common stock that are not indexed to Yellowstone's own stock as liabilities at fair value on the balance sheet. The warrants are subject to remeasurement at each balance sheet date and any change in fair value is recognized in our statement of operations. For issued or modified warrants that meet all of the criteria for equity classification, the warrants are required to be recorded as a component of additional paid-in capital at the time of issuance. For issued or modified warrants that do not meet all the criteria for equity classification, the warrants are required to be recorded as a liability at their initial fair value on the date of issuance, and each balance sheet date thereafter. Changes in the estimated fair value of the warrants are recognized as a non-cash gain or loss on the statements of operations. The fair value of the Public Warrants issued in connection with Yellowstone's Public Offering has been measured based on the listed market price of such Warrants (see Note 9).