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Significant Accounting Policies (Detail) - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016 | Dec. 31, 2015
Real Estate Asset Acquisitions [Abstract] |  |  |  |  |
Amortization of above and below market rents |  |  |  | $ (286,000) | $ 44,000
Remaining term of in-place leases (in years) |  |  |  | 10 years |
Amortization expense related to in-place leases, unamortized lease origination costs and tenant relationships |  |  |  | $ 1,224,000 | 839,000
Impairment [Abstract] |  |  |  |  |
Asset impairment | $ 700,000 |  | $ 700,000 | 948,053 | 0
Sales of Real Estate Assets [Abstract] |  |  |  |  |
Asset impairment | $ 700,000 |  | 700,000 | 948,053 | 0
Intangible Assets [Abstract] |  |  |  |  |
Impairment of definite lived assets |  |  |  | 754,000 | 556,000
Impairment of indefinite lived assets |  |  |  | 0 | 0
Impairment of goodwill |  |  |  | 0 | 0
Depreciation and Amortization of Buildings and Improvements [Abstract] |  |  |  |  |
Depreciation expense |  |  |  | 10,256,185 | 7,784,917
Cash and Cash Equivalents [Abstract] |  |  |  |  |
Deposits in financial institutions that exceeded the federally insurable limits |  |  |  | 650,000 |
Cash balances may exceed federally insured limit |  |  |  | 250,000 |
Loss on federal deposit insurance corporation |  |  |  | 0 |
Tenant Receivables [Abstract] |  |  |  |  |
Allowance for uncollectible accounts |  |  |  | 26,000 | 91,000
Deferred Leasing Costs [Abstract] |  |  |  |  |
Net deferred leasing costs |  |  |  | 1,920,000 | 1,483,000
Amortization of deferred leasing costs |  |  |  | 494,000 | 412,000
Deferred Financing Costs [Abstract] |  |  |  |  |
Unamortized deferred financing costs |  |  |  | 1,942,000 | 2,052,000
Amortization of financing costs |  | $ 956,956 | $ 1,081,520 | $ 1,447,021 | 1,286,437
Income Tax Examination Description |  |  |  | We have elected to be taxed as a REIT under Sections 856 through 860 of the Code, for federal income tax purposes. To maintain our qualification as a REIT, we are required to distribute at least 90% of our REIT taxable income to our stockholders and meet the various other requirements imposed by the Code relating to such matters as operating results, asset holdings, distribution levels and diversity of stock ownership |
Percentage of distributed taxable income to qualify as REIT |  |  |  | 90.00% |
Revenue Recognition [Abstract] |  |  |  |  |
Deferred rent receivable |  |  |  | $ 0 | $ 0
Loss Per Common Share [Abstract] |  |  |  |  |
Anti-dilutive shares excluded from computation of diluted earnings per share |  |  |  | 643,510 | 722,019
Adjustments for New Accounting Principle, Early Adoption [Member] | Restricted Cash [Member] |  |  |  |  |
Loss Per Common Share [Abstract] |  |  |  |  |
New accounting pronouncement effect, restricted cash |  |  |  | $ 4,300,000 | $ 6,800,000
Mortgage Payable |  |  |  |  |
Deferred Financing Costs [Abstract] |  |  |  |  |
Amortization of financing costs |  |  |  | 433,000 | 335,000
Series B Preferred Stock [Member] |  |  |  |  |
Deferred Financing Costs [Abstract] |  |  |  |  |
Unamortized deferred financing costs |  |  |  | 592,000 | 1,606,000
Series B Preferred Stock [Member] | Mortgage Payable |  |  |  |  |
Deferred Financing Costs [Abstract] |  |  |  |  |
Amortization of financing costs |  |  |  | $ 1,014,000 | $ 952,000
Minimum [Member] |  |  |  |  |
Deferred Leasing Costs [Abstract] |  |  |  |  |
Amortization period of leased assets |  |  |  | 1 year |
Maximum [Member] |  |  |  |  |
Deferred Leasing Costs [Abstract] |  |  |  |  |
Amortization period of leased assets |  |  |  | 5 years |
Building and Building Improvements [Member] |  |  |  |  |
Depreciation and Amortization of Buildings and Improvements [Abstract] |  |  |  |  |
Estimated useful life |  |  |  | 39 years |
Assets Leased to Others [Member] | Minimum [Member] |  |  |  |  |
Depreciation and Amortization of Buildings and Improvements [Abstract] |  |  |  |  |
Estimated useful life |  |  |  | 1 year |
Assets Leased to Others [Member] | Maximum [Member] |  |  |  |  |
Depreciation and Amortization of Buildings and Improvements [Abstract] |  |  |  |  |
Estimated useful life |  |  |  | 10 years |
Furniture and Fixtures [Member] | Minimum [Member] |  |  |  |  |
Depreciation and Amortization of Buildings and Improvements [Abstract] |  |  |  |  |
Estimated useful life |  |  |  | 4 years |
Furniture and Fixtures [Member] | Maximum [Member] |  |  |  |  |
Depreciation and Amortization of Buildings and Improvements [Abstract] |  |  |  |  |
Estimated useful life |  |  |  | 5 years |

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- Definition This element represents the amortization of deferred leasing fees incurred by the lessor and amortized over the term of the lease. Such fees represent (a) costs to originate a lease incurred in transactions with independent third parties that (i) result directly from and are essential to acquire that lease and (ii) would not have been incurred had that leasing transaction not occurred and (b) certain costs directly related to specified activities performed by the lessor for that lease. Those activities are: evaluating the prospective lessee's financial condition; evaluating and recording guarantees, collateral, and other security arrangements; negotiating lease terms; preparing and processing lease documents; and closing the transaction. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 25 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=77902619&loc=d3e40246-112709 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.3) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
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- Definition For a classified balance sheet, the cumulative difference between the rental income or payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense, by the lessor or lessee, respectively, more than one year after the balance sheet date. Such receivable is reduced by allowances attributable to, for instance, credit risk associated with a lessee. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3(a)(4)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=77902458&loc=d3e39927-112707 + Details
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