Summary of Significant Accounting Policies (Policies)	6 Months Ended
Summary of Significant Accounting Policies (Policies)	Jun. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Accounting. Our financial records are maintained on the accrual basis of accounting whereby revenues are recognized when earned and expenses are recorded when incurred.
Use of estimates	Use of estimates. In order to conform with U.S. GAAP, management, in preparation of our consolidated financial statements, is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of June 30, 2017 and December 31, 2016, and the reported amounts of revenues and expenses for the three and six months ended June 30, 2017 and 2016. Actual results could differ from those estimates. Significant estimates include fair value of properties acquired, estimated useful lives of properties, allowance for bad debt, impairment, deferred taxes and the related valuation allowance for deferred taxes, and these significant estimates, as well as other estimates and assumptions, may change in the near term.
Cash and cash equivalents	Cash and cash equivalents. We consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Cash and cash equivalents as of June 30, 2017 and December 31, 2016 consisted of demand deposits at commercial banks and brokerage accounts. We maintain our cash in bank accounts that are federally insured.
Acquired Properties and Acquired Lease Intangibles	Acquired Properties and Acquired Lease Intangibles. We allocate the purchase price of the acquired properties to land, building and improvements, identifiable intangible assets and to the acquired liabilities based on their respective fair values at the time of purchase. Identifiable intangibles include amounts allocated to acquired out-of-market leases, the value of in-place leases and customer relationship value, if any. We determine fair value based on estimated cash flow projections that utilize appropriate discount and capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known trends and specific market and economic conditions that may affect the property. Factors considered by management in our analysis of determining the as-if-vacant property value include an estimate of carrying costs during the expected lease-up periods considering market conditions, and costs to execute similar leases. In estimating carrying costs, management includes real estate taxes, insurance and estimates of lost rentals at market rates during the expected lease-up periods, tenant demand and other economic conditions. Management also estimates costs to execute similar leases including leasing commissions, tenant improvements, legal and other related expenses. Intangibles related to out-of-market leases and in-place lease value are recorded as acquired lease intangibles and are amortized as an adjustment to rental revenue or amortization expense, as appropriate, over the remaining terms of the underlying leases. Premiums or discounts on acquired out-of-market debt are amortized to interest expense over the remaining term of such debt.
Depreciation	Depreciation. Depreciation is computed using the straight-line method over the estimated useful lives of 5 to 39 years for improvements and buildings, respectively. Tenant improvements are depreciated using the straight-line method over the life of the improvement or remaining term of the lease, whichever is shorter.
Impairment	Impairment. We review our properties for impairment at least annually or whenever events or changes in circumstances indicate that the carrying amount of the assets, including accrued rental income, may not be recoverable through operations. We determine whether an impairment in value has occurred by comparing the estimated future cash flows (undiscounted and without interest charges), including the estimated residual value of the property, with the carrying cost of the property. If impairment is indicated, a loss will be recorded for the amount by which the carrying value of the property exceeds its fair value. Management has determined that there has been no impairment in the carrying value of our real estate assets as of June 30, 2017.
Accrued Rents and Accounts Receivable	Accrued Rents and Accounts Receivable. Included in accrued rent and accounts receivable are base rents, tenant reimbursements and receivables attributable to recording rents on a straight-line basis. An allowance for the uncollectible portion of accrued rents and accounts receivable is determined based upon customer credit-worthiness (including expected recovery of our claim with respect to any tenants in bankruptcy), historical bad debt levels, and current economic trends.
Unamortized Lease Commissions and Deferred Legal Costs	Unamortized Lease Commissions and Deferred Legal Costs. Leasing commissions and deferred legal costs are amortized using the straight-line method over the terms of the related lease agreements. Loan costs are amortized on the straight-line method over the terms of the loans, which approximates the interest method. Costs allocated to in-place leases whose terms differ from market terms related to acquired properties are amortized over the remaining life of the respective leases.
Prepaids and Other assets	Prepaids and Other assets. Prepaids and other assets include escrows established pursuant to certain mortgage financing arrangements for real estate taxes and insurance.
Noncontrolling Interests	Noncontrolling Interests. Noncontrolling interests are the portion of equity in a subsidiary not attributable to a parent. The ownership interests not held by the parent are considered noncontrolling interests. Accordingly, we have reported noncontrolling interest in equity on the consolidated balance sheets but separate from Pillarstone’s equity. On the consolidated statements of operations and comprehensive income, subsidiaries are reported at the consolidated amount, including both the amount attributable to Pillarstone and noncontrolling interest.
Revenue recognition	Revenue recognition. All leases on our properties are classified as operating leases, and the related rental income is recognized on a straight-line basis over the terms of the related leases. Differences between rental income earned and amounts due per the respective lease agreements are capitalized or charged, as applicable, to accrued rents and accounts receivable. Percentage rents are recognized as rental income when the thresholds upon which they are based have been met. Recoveries from tenants for taxes, insurance, and other operating expenses are recognized as revenues in the period the corresponding costs are incurred. We have established an allowance for doubtful accounts against the portion of tenant accounts receivable which is estimated to be uncollectible.
Stock-based compensation	Stock-based compensation. The Company accounts for stock-based compensation in accordance with ASC 718, "Compensation - Stock Compensation," which addresses the accounting for stock-based payment transactions in which an enterprise receives employee services in exchange for (a) equity instruments of the enterprise or (b) liabilities that are based on the fair value of the enterprise’s equity instruments or that may be settled by the issuance of such equity instruments. ASC 718 generally requires that these transactions be accounted for using a fair-value-based method. The Company uses the Black-Scholes option-pricing model to determine the fair-value of stock-based awards.
Income Taxes	Income taxes. Because we have not elected to be taxed as a REIT for federal income tax purposes, we account for income taxes using the liability method under which deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities using enacted tax rates in effect for the period in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. We are also subject to certain state and local income, excise and franchise taxes. The provision for state and local taxes has been reflected in provision for income taxes in the consolidated statements of operations and has not been separately stated due to its insignificance. The Company evaluates potential uncertain tax positions on an annual basis in conjunction with the board of trustees and its tax accountants. Authoritative literature provides a two-step approach to recognize and measure tax benefits when realization of the benefits is uncertain. The first step is to determine whether the benefit meets the more-likely-than-not condition for recognition and the second step is to determine the amount to be recognized based on the cumulative probability that exceeds 50%.
Concentration of Risk	Concentration of Risk. Substantially all of our revenues are obtained from office and warehouse locations in the Dallas-Fort Worth and Houston metropolitan areas. We maintain cash accounts in major U.S. financial institutions. The terms of these deposits are on demand to minimize risk. The balances of these accounts sometimes exceed the federally insured limits, although no losses have been incurred in connection with these deposits.
Recent accounting pronouncements	Recent accounting pronouncements. In May 2014, the FASB issued guidance, as amended in subsequent updates, establishing a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most of the existing revenue recognition guidance. The standard also requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services and also requires certain additional disclosures. This guidance became effective for the reporting periods beginning on or after December 15, 2017, and interim periods within those fiscal years. We have adopted this guidance on a modified retrospective basis beginning January 1, 2018 and do not expect this standard to have a material impact on our consolidated financial statements. In February 2016, the FASB issued guidance requiring lessees to recognize a lease liability and a right-of-use asset for all leases. Lessor accounting will remain largely unchanged with the exception of changes related to costs which qualify as initial direct costs. The guidance will also require new qualitative and quantitative disclosures to help financial statement users better understand the timing, amount and uncertainty of cash flows arising from leases. This guidance will be effective for reporting periods beginning on or after December 15, 2018, with early adoption permitted. We will adopt this guidance on a modified retrospective basis beginning January 1, 2019, and such adoption will result in certain costs (primarily legal costs related to lease negotiations) being expensed rather than capitalized. We capitalized $12,000 in legal related costs for the six months ended June 30, 2017. We did not capitalize any legal related costs for the three months ended June 30, 2017. In November 2016, the FASB issued guidance requiring that the statement of cash flows explain the change during the period in the total cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. This guidance will become effective for the reporting periods beginning on or after December 15, 2017, and interim periods within those fiscal years. We adopted this guidance effective January 1, 2018, and we have reconciled cash and cash equivalents and restricted cash and restricted cash equivalents on a retrospective basis, whereas under the previous guidance, we reported restricted cash and restricted cash equivalents under cash flows from financing activities. In January 2017, the FASB issued guidance clarifying the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. This guidance will become effective for the reporting periods beginning on or after December 15, 2017, and interim periods within those fiscal years. We adopted this guidance on a prospective basis beginning January 1, 2018 and believe the majority of our future acquisitions will qualify as asset acquisitions and the associated transaction costs will be capitalized as opposed to expensed under previous guidance. In February 2017, the FASB issued guidance clarifying the scope of asset derecognition guidance, added guidance for partial sales of nonfinancial assets and clarified recognizing gains and losses from the transfer of nonfinancial assets in contracts with noncustomers. This guidance will become effective for the reporting periods beginning on or after December 15, 2017, and interim periods within those fiscal years. We adopted this guidance on a modified retrospective basis beginning January 1, 2018, and the adoption of this guidance did not have a material impact on our consolidated financial statements.