Steadfast Income REIT 10-K 29 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 20, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	Steadfast Income REIT, Inc.
Entity Central Index Key	1,468,010
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		75,298,154
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 0

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Real Estate:
Land	$ 115,023,911	$ 114,972,911
Building and improvements	972,272,325	962,926,584
Other intangible assets	2,644,263	2,644,263
Total real estate held for investment, cost	1,089,940,499	1,080,543,758
Less accumulated depreciation and amortization	(193,075,058)	(147,507,076)
Total real estate held for investment, net	896,865,441	933,036,682
Real estate held for sale, net	129,849,889	528,498,193
Total real estate, net	1,026,715,330	1,461,534,875
Cash and cash equivalents	171,228,485	66,224,027
Restricted cash	31,442,700	15,466,891
Short-term investments	0	30,084,750
Investment in unconsolidated joint venture	8,133,156	0
Rents and other receivables	2,737,800	2,750,520
Assets related to real estate held for sale	2,424,823	12,086,960
Other assets	3,258,584	4,786,762
Total assets	1,245,940,878	1,592,934,785
Liabilities:
Accounts payable and accrued liabilities	29,617,317	30,417,436
Notes payable:
Mortgage notes payable, net	683,326,105	683,977,182
Credit facility, net	90,222,098	88,578,626
Notes payable related to real estate held for sale, net	102,237,735	445,160,472
Total notes payable, net	875,785,938	1,217,716,280
Distributions payable	4,595,301	4,625,355
Due to affiliates	1,967,129	2,787,566
Liabilities related to real estate held for sale	3,327,420	16,959,905
Total liabilities	915,293,105	1,272,506,542
Commitments and contingencies (Note 10)
Stockholders’ Equity:
Preferred stock, $0.01 par value per share; 100,000,000 shares authorized, no shares issued and outstanding	0	0
Additional paid-in capital	664,110,915	672,018,194
Cumulative distributions and net losses	(334,217,946)	(352,351,990)
Total stockholders’ equity	330,647,773	320,428,243
Total liabilities and stockholders’ equity	1,245,940,878	1,592,934,785
Common stock $0.01 par value per share; 999,999,000 shares authorized, 76,202,862 and 76,674,502 shares issued and outstanding [Member]
Notes payable:
Distributions payable	4,595,301	4,625,355
Stockholders’ Equity:
Common stock value	754,794	762,029
Convertible stock, $0.01 par value per share; 1,000 shares authorized, issued and outstanding [Member]
Stockholders’ Equity:
Common stock value	$ 10	$ 10

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parentheticals) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Stockholders’ Equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, shares outstanding (in shares)	0	0
Preferred stock, shares issued (in shares)	0	0
Common Stock [Member]
Stockholders’ Equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	999,999,000	999,999,000
Common stock, shares issued (in shares)	75,479,409	76,202,862
Common stock, shares outstanding (in shares)	75,479,409	76,202,862
Convertible Stock [Member]
Stockholders’ Equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000	1,000
Common stock, shares issued (in shares)	1,000	1,000
Common stock, shares outstanding (in shares)	1,000	1,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues:
Rental income	$ 188,019,112	$ 192,088,348	$ 186,264,470
Tenant reimbursements and other	24,950,128	26,149,184	23,126,188
Total revenues	212,969,240	218,237,532	209,390,658
Expenses:
Operating, maintenance and management	58,347,903	57,832,187	53,915,306
Real estate taxes and insurance	35,114,937	36,507,827	35,825,445
Fees to affiliates	21,960,145	25,440,718	21,927,913
Depreciation and amortization	67,755,152	69,513,484	65,640,196
Interest expense	44,114,130	40,551,427	39,149,018
Loss on debt extinguishment	2,380,051	4,932,369	0
General and administrative expenses	6,732,330	9,039,171	5,949,993
Acquisition costs	0	0	7,145
Total expenses	236,404,648	243,817,183	222,415,016
Loss before other income (expense)	(23,435,408)	(25,579,651)	(13,024,358)
Equity in loss of unconsolidated joint venture	(663,896)	0	0
Gain on sales of real estate, net	96,573,171	0	0
Total other income (loss)	95,909,275	0	0
Net income (loss)	$ 72,473,867	$ (25,579,651)	$ (13,024,358)
Income (loss) per common share — basic and diluted (in dollars per share)	$ 0.96	$ (0.34)	$ (0.18)
Weighted average number of common shares outstanding — basic (in shares)	75,794,705	76,195,083	76,335,114
Weighted average number of common shares outstanding — diluted (in shares)	75,807,710	76,195,083	76,335,114

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)	Total	Common Stock [Member]	Common Stock [Member]Common Stock [Member]	Common Stock [Member]Convertible Stock [Member]	Additional Paid- In Capital [Member]	Cumulative Distributions & Net Losses [Member]
Beginning Balance (in shares) at Dec. 31, 2014			76,858,483	1,000
Beginning Balance at Dec. 31, 2014	$ 477,063,230		$ 768,585	$ 10	$ 680,138,132	$ (203,843,497)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			14,008
Issuance of common stock	78		$ 140		(62)
Transfers to redeemable common stock	(1,000,000)				(1,000,000)
Redemption of common stock (in shares)			(197,989)
Redemption of common stock	(2,000,000)		$ (1,980)		(1,998,020)
Distributions declared	(55,076,217)					(55,076,217)
Amortization of stock-based compensation	184,350				184,350
Change in value of restricted common stock to Advisor	300,440				300,440
Net income (loss)	(13,024,358)					(13,024,358)
Ending Balance (in shares) at Dec. 31, 2015			76,674,502	1,000
Ending Balance at Dec. 31, 2015	406,447,523		$ 766,745	$ 10	677,624,840	(271,944,072)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			7,500
Issuance of common stock	0		$ 75		(75)
Transfers to redeemable common stock	(1,000,000)				(1,000,000)
Redemption of common stock (in shares)			(479,140)
Redemption of common stock	(5,000,000)		$ (4,791)		(4,995,209)
Distributions declared	(54,828,267)	$ (54,828,267)				(54,828,267)
Amortization of stock-based compensation	76,285				76,285
Change in value of restricted common stock to Advisor	312,353				312,353
Net income (loss)	(25,579,651)					(25,579,651)
Ending Balance (in shares) at Dec. 31, 2016			76,202,862	1,000
Ending Balance at Dec. 31, 2016	320,428,243		$ 762,029	$ 10	672,018,194	(352,351,990)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			7,500
Issuance of common stock	0		$ 75		(75)
Redemption of common stock (in shares)			(730,953)
Redemption of common stock	(8,000,000)		$ (7,310)		(7,992,690)
Distributions declared	(54,339,823)	$ (54,339,823)				(54,339,823)
Amortization of stock-based compensation	85,486				85,486
Net income (loss)	72,473,867					72,473,867
Ending Balance (in shares) at Dec. 31, 2017			75,479,409	1,000
Ending Balance at Dec. 31, 2017	$ 330,647,773		$ 754,794	$ 10	$ 664,110,915	$ (334,217,946)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net income (loss)	$ 72,473,867	$ (25,579,651)	$ (13,024,358)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	67,755,152	69,513,484	65,640,196
Amortization of deferred financing costs	1,839,952	1,723,186	1,479,710
Amortization of stock-based compensation	85,486	76,285	184,350
Change in value of restricted common stock to Advisor	0	312,353	300,440
Amortization of loan premiums and discounts	(1,129,960)	(1,243,385)	(1,234,793)
Change in fair value of interest rate cap agreements	604,545	(61,698)	2,032,746
Loss on debt extinguishment	2,380,051	4,932,369	0
Gain on sales of real estate	(96,573,171)	0	0
Insurance claim recoveries	(352,497)	(993,527)	0
Loss on disposal of buildings and improvements	147,085	892,396	0
Unrealized gain on short-term investments	(278,883)	(84,750)	0
Equity in loss of unconsolidated joint venture	663,896	0	0
Changes in operating assets and liabilities:
Restricted cash for operating activities	3,314,163	(481,918)	(2,822,331)
Rents and other receivables	(333,347)	(8,509)	(749,701)
Other assets	960,983	(250,396)	326,182
Accounts payable and accrued liabilities	(3,106,834)	5,246,172	(209,027)
Due to affiliates	(1,372,025)	267,009	(499,327)
Net cash provided by operating activities	47,078,463	54,259,420	51,424,087
Cash Flows from Investing Activities:
Short-term investments	30,363,633	(30,000,000)	0
Cash contribution to unconsolidated joint venture	(3,854,197)	0	0
Additions to real estate investments	(16,401,961)	(28,268,601)	(29,908,727)
Restricted cash for investing activities	(128,195)	628,878	600,459
Purchase of interest rate cap agreements	(37,350)	(259,000)	(351,950)
Proceeds from sales of real estate, net	115,418,937	0	0
Proceeds from insurance claims	352,497	993,527	0
Net cash provided by (used in) investing activities	125,713,364	(56,905,196)	(29,660,218)
Cash Flows from Financing Activities:
Proceeds from issuance of mortgage notes payable	17,638,751	428,196,350	110,986,313
Principal payments on mortgage notes payable	(22,745,424)	(557,964,896)	(58,058,174)
Borrowings from credit facilities	0	251,124,750	6,000,000
Principal payments on credit facilities	0	(16,000,000)	(20,000,000)
Payment of deferred financing costs	(310,819)	(5,489,473)	(1,057,405)
Payment of debt extinguishment costs	0	(3,202,337)	0
Distributions to common stockholders	(54,369,877)	(54,871,173)	(55,087,333)
Redemptions of common stock	(8,000,000)	(5,000,000)	(2,000,000)
Net cash (used in) provided by financing activities	(67,787,369)	36,793,221	(19,216,599)
Net increase in cash and cash equivalents	105,004,458	34,147,445	2,547,270
Cash and cash equivalents, beginning of year	66,224,027	32,076,582	29,529,312
Cash and cash equivalents, end of year	171,228,485	66,224,027	32,076,582
Supplemental Disclosure of Cash Flow Information:
Interest paid, net of amounts capitalized of $0, $80,166 and $153,920 for the years ended December 31, 2017, 2016 and 2015, respectively	43,477,719	39,622,084	36,734,805
Supplemental Disclosure of Noncash Transactions:
Decrease in distributions payable	(30,054)	(42,906)	(11,194)
Distributions paid to common stockholders through common stock issuances pursuant to the distribution reinvestment plan	0	0	78
Increase in redeemable common stock payable	0	1,000,000	1,000,000
Non-cash contribution to unconsolidated joint venture	(3,281,298)	0	0
Assets and liabilities deconsolidated in connection with property sales:
Real estate, net	(382,696,431)	0	0
Notes payable, net	337,214,942	0	0
Restricted cash	(7,699,698)	0	0
Rents and other receivables	(346,067)	0	0
Accounts payable and accrued liabilities	11,330,808	0	0
Increase in accounts payable and accrued liabilities from additions to investment in unconsolidated joint venture	398,817	0	0
(Decrease) increase in accounts payable and accrued liabilities from additions to real estate investments	(607,801)	378,711	433,557
(Decrease) increase in due to affiliates from additions to real estate investments	$ (15,037)	$ (161,652)	$ 142,046

CONSOLIDATED STATEMENTS OF CAS7

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parentheticals) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Interest paid, net of amounts capitalized of $0, $80,166 and $153,920 for the years ended December 31, 2017, 2016 and 2015, respectively	$ 0	$ 80,166	$ 153,920

Organization and Business

Organization and Business	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business	Organization and Business Steadfast Income REIT, Inc. (the “Company”) was formed on May 4, 2009, as a Maryland corporation that has elected to be taxed as a real estate investment trust (“REIT”). On June 12, 2009, the Company was initially capitalized pursuant to the sale of 22,223 shares of common stock to Steadfast REIT Investments, LLC (the “Sponsor”) at a purchase price of $9.00 per share for an aggregate purchase price of $200,007 . On July 10, 2009, Steadfast Income Advisor, LLC (the “Advisor”), a Delaware limited liability company formed on May 1, 2009, invested $1,000 in the Company in exchange for 1,000 shares of convertible stock (the “Convertible Stock”) as described in Note 7. The Company owns a diverse portfolio of real estate investments, primarily in the multifamily sector, located throughout the United States. As of December 31, 2017 , the Company owned 48 multifamily properties comprising a total of 12,156 apartment homes, an additional 21,130 square feet of rentable commercial space at two properties and a 10% interest in one unconsolidated joint venture that owned 12 multifamily properties comprised of a total of 3,301 apartment homes. Private Offering On October 13, 2009, the Company commenced a private offering of up to $94,000,000 in shares of the Company’s common stock at a purchase price of $9.40 per share (with discounts available for certain categories of purchasers) (the “Private Offering”). The Company offered its shares of common stock for sale in the Private Offering pursuant to a confidential private placement memorandum and only to persons that were “accredited investors,” as that term is defined under the Securities Act of 1933, as amended (the “Securities Act”), and Regulation D promulgated thereunder. On July 9, 2010, the Company terminated the Private Offering and on July 19, 2010, the Company commenced its registered Public Offering (defined and described below). The Company sold 637,279 shares of common stock in the Private Offering for gross offering proceeds of $5,844,325 . Public Offering On July 19, 2010, the Company commenced its initial public offering of up to a maximum of 150,000,000 shares of common stock for sale to the public at an initial price of $10.00 per share (with discounts available for certain categories of purchasers) (the “Primary Offering”). The Company also offered up to 15,789,474 shares of common stock for sale pursuant to the Company’s distribution reinvestment plan (the “DRP,” and together with the Primary Offering, the “Public Offering”) at an initial price of $9.50 per share. The Company terminated its Public Offering on December 20, 2013 . Following termination of the Public Offering, the Company continued to offer shares of common stock pursuant to the DRP until the Company’s board of directors suspended the DRP effective with distributions earned beginning on December 1, 2014. Through December 20, 2013 , the Company sold 73,608,337 shares of common stock in the Public Offering for gross proceeds of $745,389,748 , including 1,588,289 shares of common stock issued pursuant to the DRP for gross offering proceeds of $15,397,232 . On March 10, 2015, the Company’s board of directors determined an estimated value per share of the Company’s common stock of $10.35 as of December 31, 2014. On February 25, 2016, the Company’s board of directors determined an estimated value per share of the Company’s common stock of $11.44 as of December 31, 2015. On February 15, 2017, the Company’s board of directors determined an estimated value per share of the Company’s common stock of $11.65 as of December 31, 2016. See “ —N ote 14. Subsequent Events” for further information regarding the estimated value per share. The business of the Company is externally managed by the Advisor pursuant to the Advisory Agreement by and among the Company, Steadfast Income REIT Operating Partnership, L.P., a Delaware limited partnership formed on July 6, 2009 (the “Operating Partnership) and the Advisor (as amended, the “Advisory Agreement”), which is subject to annual renewal by the Company’s board of directors. The current term of the Advisory Agreement expires on November 15, 2018 . Subject to certain restrictions and limitations, the Advisor manages the Company’s day-to-day operations, manages the Company’s portfolio of properties and real estate-related assets, sources and presents investment opportunities to the Company’s board of directors and provides investment management services on the Company’s behalf. Steadfast Capital Markets Group, LLC (the “Dealer Manager”), an affiliate of the Company, served as the dealer manager for the Public Offering. Effective December 27, 2017, the Dealer Manager changed its name from “Steadfast Capital Markets Group, LLC” to “Stira Capital Markets Group, LLC.” The Advisor, along with the Dealer Manager, also provides marketing, investor relations and other administrative services on the Company’s behalf. Substantially all of the Company’s business is conducted through the Operating Partnership. The Company is the sole general partner of the Operating Partnership. The Company and Advisor entered into an Amended and Restated Limited Partnership Agreement of the Operating Partnership (the “Partnership Agreement”) on September 28, 2009. The Partnership Agreement provides that the Operating Partnership is operated in a manner that will enable the Company to (1) satisfy the requirements for being classified as a REIT for tax purposes, (2) avoid any federal income or excise tax liability and (3) ensure that the Operating Partnership will not be classified as a “publicly traded partnership” for purposes of Section 7704 of the Internal Revenue Code of 1986, as amended (the “Internal Revenue Code”), which classification could result in the Operating Partnership being taxed as a corporation, rather than as a partnership. In addition to the administrative and operating costs and expenses incurred by the Operating Partnership in acquiring and operating real properties, the Operating Partnership will pay all of the Company’s administrative costs and expenses, and such expenses will be treated as expenses of the Operating Partnership.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Principles of Consolidation and Basis of Presentation The consolidated financial statements include the accounts of the Company, the consolidated variable interest entity (“VIE”) that the Company controls and of which the Company is the primary beneficiary, and the Operating Partnership’s subsidiaries. All significant intercompany balances and transactions are eliminated in consolidation. The financial statements of the Company’s subsidiaries are prepared using accounting policies consistent with those of the Company. The Operating Partnership is a VIE as the limited partner lacks substantive kick-out rights and substantive participating rights. The Company is the primary beneficiary of, and consolidates, the Operating Partnership. The accompanying consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) as contained within the Financial Accounting Standards Board (“FASB”), Accounting Standards Codification (“ASC”) and the rules and regulations of the SEC. Square footage, occupancy and certain other measures used to describe real estate included in the notes to the consolidated financial statements are presented on an unaudited basis. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates. Real Estate Assets Depreciation and Amortization Real estate costs related to the development, construction and improvement of properties are capitalized. Acquisition costs related to business combinations are expensed as incurred. Acquisition costs related to asset acquisitions are capitalized. Repair and maintenance and tenant turnover costs are charged to expense as incurred and significant replacements and betterments are capitalized. Repair and maintenance and tenant turnover costs include all costs that do not extend the useful life of the real estate asset. The Company considers the period of future benefit of an asset to determine its appropriate useful life and anticipates the estimated useful lives of assets by class to be generally as follows: Buildings 27.5 years Building improvements 5-25 years Tenant improvements Shorter of lease term or expected useful life Tenant origination and absorption costs Remaining term of related lease Furniture, fixtures, and equipment 5-10 years Real Estate Purchase Price Allocation Prior to the Company’s adoption of ASU 2017-01 (as later defined) in January 2017, the Company recorded the acquisition of income-producing real estate or real estate that will be used for the production of income as a business combination. All assets acquired and liabilities assumed in a business combination were measured at their acquisition-date fair values. Acquisition costs were expensed as incurred. Upon adoption of ASU 2017-01, the Company records the acquisition of income-producing real estate or real estate that are used for the production of income as an asset acquisition. All assets acquired and liabilities assumed in the asset acquisition are measured at their acquisition date fair values. Acquisition costs are capitalized and allocated between land, buildings and improvements and tenant origination and associated costs on the consolidated balance sheet. The Company assesses the acquisition-date fair values of all tangible assets, identifiable intangible assets and assumed liabilities using methods similar to those used by independent appraisers (e.g., discounted cash flow analysis) and that utilize appropriate discount and/or capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including historical operating results, known and anticipated trends, and market and economic conditions. The fair value of tangible assets of an acquired property considers the value of the property as if it was vacant. Intangible assets include the value of in-place leases, which represents the estimated value of the net cash flows of the in-place leases to be realized, as compared to the net cash flows that would have occurred had the property been vacant at the time of acquisition and subject to lease-up. The Company estimates the value of tenant origination and absorption costs by considering the estimated carrying costs during hypothetical expected lease-up periods, considering current market conditions. In estimating carrying costs, the Company estimates the amount of lost rentals using market rates during the expected lease-up periods. The Company amortizes the value of in-place leases to expense over the remaining non-cancelable term of the respective leases. Should a tenant terminate its lease, the unamortized portion of the in-place lease value and customer relationship intangibles would be charged to expense in that period. The Company records above-market and below-market in-place lease values for acquired properties based on the present value (using an interest rate that reflects the risks associated with the leases acquired) of the difference between (1) the contractual amounts to be paid pursuant to the in-place leases and (2) the Company’s estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining non-cancelable term of the lease. The Company amortizes any capitalized above-market or below-market lease values as a reduction or increase to rental income over the remaining non-cancelable terms of the respective leases. The total amount of other lease-related intangible assets acquired will be further allocated to in-place lease values and customer relationship intangible values based on the Company’s evaluation of the specific characteristics of each tenant’s lease and its overall relationship with that respective tenant. Characteristics that the Company considers in allocating these values include the nature and extent of existing business relationships with the tenant, growth prospects for developing new business with the tenant, and the tenant’s credit quality and expectations of lease renewals (including those existing under the terms of the lease agreement), among other factors. The total amount of non-lease-related intangible assets, including amenity access agreements, tax abatement agreements or other contract rights assumed as part of the acquisition of certain properties, will be allocated to other intangible assets based on the present value of the difference between contractual amounts to be paid pursuant to the contracts assumed and the Company’s estimate of the fair market contract rates for corresponding contracts measured over a period equal to the remaining non-cancelable term of the contracts assumed. Other intangible assets are amortized using the straight-line method over the remaining non-cancelable term of the related contracts. Estimates of the fair values of the tangible assets, identifiable intangible assets and assumed liabilities require the Company to make significant assumptions to estimate market lease rates, property-operating expenses, carrying costs during lease-up periods, discount rates, market absorption periods, and the number of years the property will be held for investment. The use of inappropriate assumptions could result in an incorrect valuation of acquired tangible assets, identifiable intangible assets and assumed liabilities, which could impact the amount of the Company’s net income (loss). Sale of Real Estate Assets Property sales or dispositions are recorded when title transfers to unrelated third parties, contingencies have been removed and sufficient cash consideration has been received by the Company. Upon disposition, the related costs and accumulated depreciation are removed from the respective accounts. Any gain or loss on sale is recognized in accordance with GAAP. The Company recognizes gains on sales of real estate either in total or deferred for a period of time, depending on whether a sale has been consummated, the extent of the buyer’s investment in the property being sold, whether the receivable is subject to future subordination, and the degree of the Company’s continuing involvement with the property after the sale. If the criteria for profit recognition under the full-accrual method are not met, the Company will defer gain recognition and account for the continued operations of the property by applying the percentage-of-completion, reduced profit, deposit, installment or cost recovery method, as appropriate, until the appropriate criteria are met. The Company classifies real estate assets as real estate held for sale once the criteria, as defined by GAAP, have been met. Impairment of Real Estate Assets The Company accounts for its real estate assets in accordance with ASC 360— Property, Plant and Equipment (“ASC 360”). ASC 360 requires the Company to continually monitor events and changes in circumstances that could indicate that the carrying amounts of the Company’s real estate and related intangible assets may not be recoverable. When indicators of potential impairment suggest that the carrying value of real estate and related intangible assets and liabilities may not be recoverable, the Company assesses the recoverability of the assets by estimating whether the Company will recover the carrying value of the asset through its undiscounted future cash flows and its eventual disposition. Based on this analysis, if the Company does not believe that it will be able to recover the carrying value of the real estate and related intangible assets and liabilities, the Company records an impairment loss to the extent that the carrying value exceeds the estimated fair value of the real estate and related intangible assets and liabilities. If any assumptions, projections or estimates regarding an asset changes in the future, the Company may have to record an impairment to reduce the net book value of such individual asset. The Company did not record any impairment loss on its real estate assets during the years ended December 31, 2017 , 2016 and 2015 . Investments in Unconsolidated Joint Ventures Equity Method The Company accounts for investments in unconsolidated joint venture entities in which it may exercise significant influence over, but does not control, using the equity method of accounting. Under the equity method, the investment is initially recorded at cost and subsequently adjusted to reflect additional contributions or distributions and the Company’s proportionate share of equity in the joint venture’s income (loss). The Company recognizes its proportionate share of the ongoing income or loss of the unconsolidated joint venture as equity in income (loss) of unconsolidated joint venture on the consolidated statements of operations. On a quarterly basis, the Company evaluates its investment in an unconsolidated joint venture for other-than-temporary impairments. Cost Method The Company accounts for investments in unconsolidated joint venture entities in which it does not have the ability to exercise significant influence and has virtually no influence over partnership operating and financial policies using the cost method of accounting. Under the cost method, income distributions from the partnership are recognized in other income. Distributions that exceed the Company’s share of earnings are applied to reduce the carrying value of its investment and any capital contributions will increase the carrying value of its investment. On a quarterly basis, the Company evaluates its investment in an unconsolidated joint venture for other-than-temporary impairments. The fair value of a cost method investment is not estimated if there are no identified events or changes in circumstances that would indicate a significant adverse effect on the fair value of the investment. Rents and Other Receivables The Company will periodically evaluate the collectability of amounts due from tenants and maintain an allowance for doubtful accounts for estimated losses resulting from the inability of tenants to make required payments under lease agreements. The Company exercises judgment in establishing these allowances and considers payment history and current credit status of tenants in developing these estimates. Due to the short-term nature of the operating leases, the Company does not maintain a deferred rent receivable related to the straight-lining of rents. Revenue Recognition The Company leases apartment and condominium units under operating leases with terms generally of one year or less. Generally, credit investigations are performed for prospective residents and security deposits are obtained. The Company will recognize minimum rent, including rental abatements, concessions and contractual fixed increases attributable to operating leases, on a straight-line basis over the term of the related lease and amounts expected to be received in later years will be recorded as deferred rents. The Company records property operating expense reimbursements due from tenants for common area maintenance, real estate taxes, and other recoverable costs in the period the related expenses are incurred. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Cash equivalents may include cash and short-term investments. Short-term investments are stated at cost, which approximates fair value. As of December 31, 2017 and 2016 , the Company had amounts in excess of federally insured limits in deposit accounts with a financial institution. The Company limits such deposits to financial institutions with high credit standing. Restricted Cash Restricted cash represents those cash accounts for which the use of funds is restricted by loan covenants and cash placed with a qualified intermediary for reinvestment under Section 1031 of the Internal Revenue Code (“1031 Exchange”). As of December 31, 2017 and 2016 , the Company had a restricted cash balance of $31,442,700 and $15,466,891 , respectively, which represents amounts set aside as impounds for future property tax payments, property insurance payments and tenant improvement payments as required by agreements with the Company’s lenders, in addition to $17,197,810 and $0 of cash proceeds from property sales that are being held by qualified intermediaries for purposes of facilitating a 1031 Exchange as of December 31, 2017 and 2016 , respectively. Short-term Investments Short-term investments consist of any highly-liquid securities that have an original maturity of less than one year but greater than three months at the time of purchase. As of December 31, 2016 , short-term investments consisted of $30,000,000 held in a certificate of deposit and is included in short-term investments on the accompanying consolidated balance sheets. The certificate of deposit originally matured on March 28, 2017; however, upon maturity, the balance was rolled into a new six-month certificate of deposit. The new certificate of deposit matured on September 26, 2017, and was not renewed. As of December 31, 2017 , there were no short-term investments. The short-term investment was classified as held-to-maturity and was recorded at the amortized cost on the accompanying consolidated balance sheets. During the years ended December 31, 2017 and December 31, 2016 , $278,883 and $84,750 was included in tenant reimbursements and other on the accompanying consolidated statements of operations. Deferred Financing Costs The Company capitalizes deferred financing costs such as commitment fees, legal fees and other third party costs associated with obtaining commitments for financing that result in a closing of such financing, as a contra liability against the respective outstanding debt balances. The Company amortizes these costs over the terms of the respective financing agreements using the effective interest method. The Company expenses unamortized deferred financing costs when the associated debt is refinanced or repaid before maturity unless specific rules are met that would allow for the carryover of such costs to the refinanced debt. Costs incurred in seeking financing transactions that do not close are expensed in the period in which it is determined that the financing will not close. Derivative Financial Instruments The Company accounts for its derivative financial instruments in accordance with ASC 815— Derivatives and Hedging . The Company’s objective in using derivatives is to add stability to interest expense and to manage the Company’s exposure to interest rate movements or other identified risks. To accomplish these objectives, the Company may use various types of derivative instruments to manage fluctuations in cash flows resulting from interest rate risk attributable to changes in the benchmark interest rate of LIBOR or other applicable benchmark rates. The Company measures its derivative instruments and hedging activities at fair value and records them as an asset or liability, depending on its rights or obligations under the applicable derivative contract. For derivatives designated as fair value hedges, the changes in the fair value of both the derivative instrument and the hedged items are recorded in earnings. Derivatives used to hedge the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For derivatives designated as cash flow hedges, the effective portions of changes in fair value of the derivatives are reported in other comprehensive income (loss) and are subsequently reclassified into earnings when the hedged item affects earnings. Changes in fair value of derivative instruments not designated as hedges and ineffective portions of hedges are recognized in earnings in the affected period. The Company assesses the effectiveness of each hedging relationship by comparing the changes in fair value or cash flows of the derivative hedging instrument with the changes in fair value or cash flows of the designated hedged item or transaction. As of December 31, 2017 , the Company did not have any derivatives designated as cash flow or fair value hedges, nor are derivatives being used for trading or speculative purposes. Fair Value Measurements Under GAAP, the Company is required to measure certain financial instruments at fair value on a recurring basis. In addition, the Company is required to measure other assets and liabilities at fair value on a non-recurring basis (e.g., carrying value of impaired real estate loans receivable and long-lived assets). Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The GAAP fair value framework uses a three-tiered approach. Fair value measurements are classified and disclosed in one of the following three categories: • Level 1: unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; • Level 2: quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and • Level 3: prices or valuation techniques where little or no market data is available that requires inputs that are both significant to the fair value measurement and unobservable. When available, the Company utilizes quoted market prices from an independent third-party source to determine fair value and will classify such items in Level 1 or Level 2. In instances where the market is not active, regardless of the availability of a nonbinding quoted market price, observable inputs might not be relevant and could require the Company to make a significant adjustment to derive a fair value measurement. Additionally, in an inactive market, a market price quoted from an independent third party may rely more on models with inputs based on information available only to that independent third party. When the Company determines the market for a financial instrument owned by the Company to be illiquid or when market transactions for similar instruments do not appear orderly, the Company uses several valuation sources (including internal valuations, discounted cash flow analysis and quoted market prices) and will establish a fair value by assigning weights to the various valuation sources. The following describes the valuation methodologies used by the Company to measure fair value, including an indication of the level in the fair value hierarchy in which each asset or liability is generally classified. Interest rate cap agreements - The Company has entered into certain interest rate cap agreements. These derivatives did not qualify as fair value hedges. Fair value was based on a model-driven valuation using the associated variable rate curve and an implied market volatility, both of which were observable at commonly quoted intervals for the full term of the interest rate cap agreements. Therefore, the Company’s interest rate cap agreements were classified within Level 2 of the fair value hierarchy and are included in other assets in the accompanying consolidated balance sheets. The following table reflects the Company’s assets required to be measured at fair value on a recurring basis on the consolidated balance sheets: December 31, 2017 Fair Value Measurements Using Level 1 Level 2 Level 3 Assets: Interest rate cap agreements $ — $ 51,646 $ — December 31, 2016 Fair Value Measurements Using Level 1 Level 2 Level 3 Assets: Interest rate cap agreements $ — $ 618,841 $ — Changes in assumptions or estimation methodologies can have a material effect on these estimated fair values. In this regard, the derived fair value estimates cannot be substantiated by comparison to independent markets and, in many cases, may not be realized in an immediate settlement of the instrument. Fair Value of Financial Instruments The accompanying consolidated balance sheets include the following financial instruments: cash and cash equivalents, restricted cash, short-term investments, rents and other receivables, accounts payable and accrued liabilities, distributions payable, due to affiliates and notes payable. The Company considers the carrying value of cash and cash equivalents, restricted cash, rents and other receivables, accounts payable and accrued liabilities and distributions payable to approximate the fair value of these financial instruments based on the short duration between origination of the instruments and their expected realization. The Company considers the carrying value of short-term investments to approximate fair value as it was recorded at amortized cost. The fair value of amounts due to affiliates is not determinable due to the related party nature of such amounts. The fair value of the notes payable is estimated using a discounted cash flow analysis using borrowing rates available to the Company for debt instruments with similar terms and maturities. As of December 31, 2017 and 2016 , the fair value of the notes payable was $878,004,294 and $1,197,015,105 , respectively, compared to the carrying value of $875,785,938 and $1,217,716,280 , respectively. The Company has determined that its notes payable are classified as Level 3 within the fair value hierarchy. Accounting for Stock-Based Compensation The Company amortizes the fair value of stock-based compensation awards to expense over the vesting period and records any dividend equivalents earned as dividends for financial reporting purposes. Stock-based compensation awards to independent directors are valued at the fair value on the date of grant and amortized as an expense over the vesting period. Awards to non-employees are remeasured at fair value each reporting period and amortized as an expense over the vesting period. Distribution Policy The Company has elected to be taxed, and currently qualifies as, a REIT beginning with its taxable year ending December 31, 2010. To maintain its qualification as a REIT, the Company intends to make distributions each taxable year equal to at least 90% of its REIT taxable income (which is determined without regard to the dividends paid deduction or net capital gain and which does not necessarily equal net income as calculated in accordance with GAAP). Distributions were based on daily record dates and calculated at a rate of $0.001964 per share per day during the year ended December 31, 2017, and the three months ended March 31, 2016. Distributions were based on daily record dates and calculated at a rate of $0.001958 per share per day during the nine months ended December 31, 2016. Each day during the period from January 1, 2017 through December 31, 2017 was a distribution record date. Distributions to stockholders are determined by the board of directors of the Company and are dependent upon a number of factors relating to the Company, including funds available for the payment of distributions, financial condition, the timing of property acquisitions, capital expenditure requirements and annual distribution requirements in order for the Company to qualify as a REIT under the Internal Revenue Code. Operating Expenses Pursuant to the Advisory Agreement, the Company is limited in the amount of certain operating expenses it may record on a rolling four-quarter basis to the greater of 2% of average invested assets and 25% of net income. Operating expenses include all costs and expenses incurred by the Company, as determined under GAAP, that in any way are related to the operation of the Company, excluding expenses of raising capital, interest payments, taxes, property operating expenses, non-cash expenditures, incentive fees, acquisition fees and expenses and investment management fees. During the four quarters ended December 31, 2017 , the Company recorded operating expenses of $4,666,862 , which is included in general and administrative expenses in the accompanying consolidated statements of operations. Operating expenses of $87,220 remain payable and are included in due to affiliates in the accompanying consolidated balance sheet as of December 31, 2017 . Income Taxes The Company elected to be taxed as a REIT under the Internal Revenue Code beginning with the tax year ended December 31, 2010. To continue to qualify as a REIT, the Company must meet certain organizational and operational requirements, including the requirement to distribute at least 90% of the Company’s annual REIT taxable income to stockholders (which is computed without regard to the dividends paid deduction or net capital gain and which does not necessarily equal net income as calculated in accordance with GAAP). As a REIT, the Company generally will not be subject to federal income tax to the extent it distributes qualifying dividends to its stockholders. If the Company fails to qualify as a REIT in any taxable year, it will be subject to federal income tax on its taxable income at regular corporate income tax rates and generally will not be permitted to qualify for treatment as a REIT for federal income tax purposes for the four taxable years following the year during which qualification is lost, unless the Internal Revenue Service grants the Company relief under certain statutory provisions. Such an event could materially adversely affect the Company’s net income and net cash available for distribution to stockholders. However, the Company believes it is organized and operates in such a manner as to qualify for treatment as a REIT. The Company follows the Income Taxes Topic of the ASC to recognize, measure, present and disclose in its accompanying consolidated financial statements uncertain tax positions that the Company has taken or expects to take on a tax return. As of December 31, 2017 and 2016 , the Company had no liabilities for uncertain tax positions that it believes should be recognized in its accompanying consolidated financial statements. Due to uncertainty regarding the realization of certain deferred tax assets, the Company has established valuation allowances, primarily in connection with the net operating loss carryforward related to the Company. The Company has no t been assessed material interest or penalties by any major tax jurisdictions. The Company’s evaluation was performed for the tax years ended December 31, 2017 and 2016 . As of December 31, 2017 , the Company’s tax returns for calendar years 2016 , 2015 and 2014 remain subject to examination by major tax jurisdictions. Per Share Data Basic earnings (loss) per share attributable to common stockholders for all periods presented are computed by dividing net income (loss) by the weighted average number of shares of the Company’s common stock outstanding during the period. Diluted earnings (loss) per share is computed based on the weighted average number of shares of the Company’s common stock and all potentially dilutive securities, if any. Distributions declared per common share assume each share was issued and outstanding each day during the period. Nonvested shares of the Company’s restricted common stock give rise to potentially dilutive shares of the Company’s common stock. In accordance with FASB ASC Topic 260-10-45, Earnings Per Share , the Company uses the two-class method to calculate earnings (loss) per share. Basic earnings (loss) per share is calculated based on dividends declared and the rights of common shares and participating securities in any undistributed earnings, which represents net income (loss) remaining after deduction of dividends declared during the period. The undistributed earnings (loss) are allocated to all outstanding common shares based on the relative percentage of each class of shares. The Company does not have any participating securities outstanding other than the shares of common stock and the unvested restricted common stock during the periods presented. Earnings (loss) attributable to the unvested restricted common stock are deducted from earnings (loss) in the computation of per share amounts where applicable. Segment Disclosure The Company has determined that it has one reportable segment with activities related to investing in multifamily properties. The Company’s investments in real estate are in different geographic regions, and management evaluates operating performance on an individual asset level. However, as each of the Company’s assets has similar economic characteristics, tenants and products and services, its assets have been aggregated into one reportable segment. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers ( Topic 606 ) (“ASU 2014-09”). The new guidance requires an entity to recognize the 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 and services. The new guidance supersedes the revenue requirements in Revenue Recognition ( Topic 605 ) and most industry-specific guidance throughout the Industry Topics of the Codification. The new guidance does not apply to lease contracts within the scope of Leases ( Topic 840 ). In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606) , which delayed the effective date of the new guidance by one year, which resulted in the new guidance being effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and is to be applied retrospectively. Early adoption is permitted, but can be no earlier than the original public entity effective date of fiscal years, and interim periods within those years, beginning after December 15, 2016. The Company has selected the modified retrospective transition method with a cumulative effect recognized as of the date of adoption and will adopt the new standard effective January 1, 2018. Based on its assessment, the Company identified limited sources of revenues from non-lease components. Based on its assessment, the Company does not expect a material impact on its revenue recognition in the consolidated financial statements because these sources of revenue are immaterial to the consolidated financial statements. The Company also does not expect a material impact from adopting this new guidance

Real Estate

Real Estate	12 Months Ended
	Dec. 31, 2017
Real Estate [Abstract]
Real Estate	Real Estate As of December 31, 2017 , the Company owned 48 multifamily properties, encompassing in the aggregate 12,156 apartment homes and an additional 21,130 square feet of rentable commercial space at two properties. The total purchase price of the Company’s real estate portfolio, including development and construction costs for apartment homes constructed by the Company, was $1,208,240,189 . As of December 31, 2017 and 2016 , the Company’s portfolio was approximately 93.8% and 93.5% occupied and the average monthly rent was $1,037 and $1,026 , respectively. As of December 31, 2017 and 2016 , accumulated depreciation and amortization related to the Company’s consolidated real estate properties and related intangibles were as follows: December 31, 2017 Assets Land Building and Improvements Other Intangible Assets Total Real Estate Held for Investment Real Estate Held for Sale Investments in real estate $ 115,023,911 $ 972,272,325 $ 2,644,263 $ 1,089,940,499 $ 158,356,486 Less: Accumulated depreciation and amortization — (192,375,859 ) (699,199 ) (193,075,058 ) (28,506,597 ) Net investments in real estate and related lease intangibles $ 115,023,911 $ 779,896,466 $ 1,945,064 $ 896,865,441 $ 129,849,889 December 31, 2016 Assets Land Building and Improvements Other Intangible Assets Total Real Estate Held for Investment Real Estate Held for Sale Investments in real estate $ 114,972,911 $ 962,926,584 $ 2,644,263 $ 1,080,543,758 $ 613,735,200 Less: Accumulated depreciation and amortization — (146,961,045 ) (546,031 ) (147,507,076 ) (85,237,007 ) Net investments in real estate and related lease intangibles $ 114,972,911 $ 815,965,539 $ 2,098,232 $ 933,036,682 $ 528,498,193 Depreciation and amortization expenses were $67,755,152 , $69,513,484 and $65,640,196 for the years ended December 31, 2017 , 2016 and 2015 , respectively. Depreciation of the Company’s buildings and improvements was $67,601,984 , $69,360,316 and $65,271,243 for the years ended December 31, 2017 , 2016 and 2015 , respectively. Amortization of the Company’s tenant origination and absorption costs was $0 , $0 and $215,786 for the years ended December 31, 2017 , 2016 and 2015 , respectively. Tenant origination and absorption costs had a weighted-average amortization period as of the date of acquisition of less than one year. At December 31, 2016 , all tenant origination and absorption costs were fully amortized and written off. Amortization of the Company’s other intangible assets was $153,168 , $153,168 and $153,167 for the years ended December 31, 2017 , 2016 and 2015 , respectively. Other intangible assets had a weighted-average amortization period as of the date of acquisition of 18.17 years. The future amortization of the Company’s acquired other intangible assets as of December 31, 2017 and thereafter is as follows: 2018 $ 153,168 2019 153,168 2020 153,168 2021 153,168 2022 153,168 Thereafter 1,179,224 $ 1,945,064 Operating Leases As of December 31, 2017 , the Company’s real estate portfolio comprised 12,156 residential apartment homes and was 95.4% leased by a diverse group of residents. For the years ended December 31, 2017 and 2016 , the Company’s real estate portfolio earned in excess of 99% and less than 1% of its rental income from residential tenants and commercial office tenants, respectively. The residential tenant lease terms consist of lease durations equal to 12 months or less. The commercial office tenant leases consist of remaining lease durations varying from 1.41 to 7.25 years. Some residential and commercial leases contain provisions to extend the lease agreements, options for early termination after paying a specified penalty and other terms and conditions as negotiated. The Company retains substantially all of the risks and benefits of ownership of the real estate assets leased to tenants. Generally, upon the execution of a lease, the Company requires security deposits from tenants in the form of a cash deposit and/or a letter of credit for commercial tenants. Amounts required as security deposits vary depending upon the terms of the respective leases and the creditworthiness of the tenant, but generally are not significant amounts. Therefore, exposure to credit risk exists to the extent that a receivable from a tenant exceeds the amount of its security deposit. Security deposits received in cash related to tenant leases are included in accounts payable and accrued liabilities in the accompanying consolidated balance sheets and totaled $3,339,602 and $5,047,792 as of December 31, 2017 and 2016 , respectively. The future minimum rental receipts from the Company’s properties under non-cancelable operating leases attributable to commercial office tenants as of December 31, 2017 and thereafter is as follows: 2018 $ 259,143 2019 180,858 2020 74,313 2021 76,535 2022 76,535 Thereafter 185,501 $ 852,885 As of December 31, 2017 and 2016 , no tenant represented over 10% of the Company’s annualized base rent and there were no significant industry concentrations with respect to its commercial leases. Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. On November 10, 2017, the Company, BREIT Steadfast MF JV LP (the “Joint Venture”), BREIT Steadfast MF Parent LLC (“BREIT LP”) and BREIT Steadfast MF GP LLC (“BREIT GP”, and together with BREIT LP, “BREIT”), executed a Contribution Agreement (the “Contribution Agreement”) whereby the Company agreed to contribute a portfolio of 20 properties owned by the Company to the Joint Venture in exchange for a combination of cash and a 10% ownership interest in the Joint Venture (the “Transaction”). BREIT LP owns a 90% interest in the Joint Venture and BREIT GP serves as the general partner of the Joint Venture. Each of BREIT LP and BREIT GP is a wholly-owned subsidiary of Blackstone Real Estate Income Trust, Inc. SIR LANDS Holdings, LLC, a newly formed wholly-owned subsidiary of the Company, holds the Company’s 10% interest in the Joint Venture. The 20 properties contributed by the Company to the Joint Venture consist of properties located in Austin, Dallas and San Antonio, Texas, Nashville, Tennessee and Louisville, Kentucky (the “LANDS Portfolio”). On November 15, 2017 (the “First Closing Date”), the Company, through certain indirect wholly-owned subsidiaries, contributed 12 apartment communities (the “First Closing Properties”) to indirect, wholly-owned subsidiaries of the Joint Venture. On January 31, 2018 (the “Second Closing Date”), the Company, through certain indirect wholly-owned subsidiaries, contributed eight apartment communities (the “Second Closing Properties”) to indirect, wholly-owned subsidiaries of the Joint Venture. For additional information on the Transaction, see “Note 4 (Investment in Unconsolidated Joint Venture).” The table below sets out the properties contributed to the Joint Venture in the Transaction: Property Units Metro First Closing Properties: Ashley Oaks 462 San Antonio Audubon Park 256 Nashville Belmont 260 Dallas Cantare at Indian Lake Village 206 Nashville Cooper Creek 123 Louisville Grayson Ridge 240 Dallas Landing at Mansfield 336 Dallas Meritage at Steiner Ranch 502 Austin Montelena 232 Austin Richland Falls 276 Nashville Rosemont at Olmos Park 144 San Antonio Trails at Buda Ranch 264 Austin 3,301 Second Closing Properties: Arbors of Carrollton 131 Dallas Hills at Fair Oaks 288 San Antonio Keystone Farms 90 Nashville Renaissance St. Andrews 216 Louisville Renaissance St. Andrews Condominiums 30 Louisville Springmarc Apartments 240 Austin Valley Farms (1) 160 Louisville Valley Farms North 128 Louisville 1,283 4,584 _______________ (1) Includes SIR Valley Farms Clubhouse, LLC. Between August 24, 2011 and May 16, 2014 , the Company, through indirect wholly owned subsidiaries, acquired the First Closing Properties , containing 3,301 apartment homes in the aggregate. The aggregate purchase price of the First Closing Properties was $318,576,792 , plus closing costs. On November 15, 2017 , the Company sold a 90% interest in the First Closing Properties for $335,430,000 , resulting in a gain of $76,135,530 , which includes reductions to the net book value of the properties due to historical depreciation and amortization expense. The purchaser of the First Closing Properties was the Joint Venture. 2017 Property Dispositions Park Place Condominiums On December 22, 2010 , the Company, through an indirect wholly owned subsidiary, acquired Park Place Condominiums , a multifamily property located in Des Moines, Iowa , containing 151 apartment homes. The purchase price of the Park Place Condominiums was $8,323,400 , plus closing costs. On September 29, 2017 , the Company sold the Park Place Condominiums for $10,325,000 , resulting in a gain of $3,455,608 , which includes reductions to the net book value of the property due to historical depreciation and amortization expense. The purchaser of the Park Place Condominiums was not affiliated with the Company or the Advisor. Windsor on the River Apartments On January 26, 2012 , the Company, through an indirect wholly owned subsidiary, acquired Windsor on the River Apartments , a multifamily property located in Cedar Rapids, Iowa , containing 424 apartment homes. The purchase price of the Windsor on the River Apartments was $33,000,000 , plus closing costs. On September 29, 2017 , the Company sold the Windsor on the River Apartments for $29,750,000 , resulting in a gain of $1,927,239 , which includes reductions to the net book value of the property due to historical depreciation and amortization expense. The purchaser of the Windsor on the River Apartments was not affiliated with the Company or the Advisor. Renaissance at Carol Stream On December 31, 2013 , the Company, through an indirect wholly owned subsidiary, acquired Renaissance at Carol Stream , a multifamily property located in Carol Stream, Illinois , containing 293 apartment homes. The purchase price of Renaissance at Carol Stream was $29,150,000 , plus closing costs. On October 30, 2017 , the Company sold Renaissance at Carol Stream for $33,900,000 , resulting in a gain of $6,688,979 , which includes reductions to the net book value of the property due to historical depreciation and amortization expense. The purchaser of Renaissance at Carol Stream was not affiliated with the Company or the Advisor. Deer Valley Apartments On April 30, 2013 , the Company, through an indirect wholly owned subsidiary, acquired Deer Valley Apartments , a multifamily property located in Lake Bluff, Illinois , containing 224 apartment homes. The purchase price of the Deer Valley Apartments was $28,600,000 , plus closing costs. On December 13, 2017 , the Company sold the Deer Valley Apartments for $31,075,000 , resulting in a gain of $5,502,148 , which includes reductions to the net book value of the property due to historical depreciation and amortization expense. The purchaser of the Deer Valley Apartments was not affiliated with the Company or the Advisor. Park Shore Apartments On September 12, 2014 , the Company, through an indirect wholly owned subsidiary, acquired Park Shore Apartments , a multifamily property located in St. Charles, Illinois , containing 160 apartment homes. The purchase price of the Park Shore Apartments was $18,350,000 , plus closing costs. On December 15, 2017 , the Company sold the Park Shore Apartments for $20,100,000 , resulting in a gain of $2,863,667 , which includes reductions to the net book value of the property due to historical depreciation and amortization expense. The purchaser of the Park Shore Apartments was not affiliated with the Company or the Advisor. The results of operations for the years ended December 31, 2017 , 2016 and 2015 , for the disposed properties, including the properties contributed to the Joint Venture, were included in continuing operations on the Company’s consolidated statements of operations and are as follows: For the Year Ended December 31, 2017 2016 2015 Revenues: Rental income $ 46,450,562 $ 51,585,026 $ 49,329,436 Tenant reimbursements and other 6,383,148 7,090,653 6,330,963 Total revenues 52,833,710 58,675,679 55,660,399 Expenses: Operating, maintenance and management 15,863,468 16,579,083 15,338,184 Real estate taxes and insurance 10,162,131 10,634,970 11,065,115 Fees to affiliates 2,087,374 2,260,569 2,171,583 Depreciation and amortization 16,659,338 19,022,464 17,830,725 Interest expense 10,406,061 9,372,856 8,230,556 Loss on debt extinguishment 2,387,552 1,495,312 — General and administrative expenses 561,437 1,175,433 337,469 Total expenses $ 58,127,361 $ 60,540,687 $ 54,973,632 Real Estate Held for Sale The Moorings Apartments As of December 31, 2017 , The Moorings Apartments , a multifamily property located in Roselle, Illinois , met all the criteria to be classified as held for sale. The Moorings Apartments was sold on January 5, 2018 . See Note 14. The real estate, other assets, mortgage notes and other liabilities related to The Moorings Apartments are disclosed separately for the periods presented in the accompanying consolidated balance sheets. Arrowhead Apartment Homes As of December 31, 2017 , Arrowhead Apartment Homes , a multifamily property located in Palatine, Illinois , met all the criteria to be classified as held for sale. Arrowhead Apartment Homes was sold on January 31, 2018 . See Note 14. The real estate, other assets, mortgage notes and other liabilities related to Arrowhead Apartment Homes are disclosed separately for the periods presented in the accompanying consolidated balance sheets. Second Closing Properties As of December 31, 2017 , the Second Closing Properties , eight multifamily properties located in the Austin, Dallas and San Antonio, Texas, Nashville, Tennessee and Louisville, Kentucky markets met all the criteria to be classified as held for sale. The Second Closing Properties were sold on January 31, 2018 . The real estate, other assets, mortgage notes and other liabilities related to the Second Closing Properties are disclosed separately for the periods presented in the accompanying consolidated balance sheets. The results of operations from The Moorings Apartments , Arrowhead Apartment Homes and the Second Closing Properties for the years ended December 31, 2017 , 2016 and 2015 , which are summarized in the following table, were included in continuing operations on the Company’s consolidated statements of operations. For the Years Ended December 31, 2017 2016 2015 Revenues $ 21,889,939 $ 21,257,326 $ 19,748,536 Expenses 19,926,810 20,705,376 19,322,136 Total Income $ 1,963,129 $ 551,950 $ 426,400

Investment in Unconsolidated Jo

Investment in Unconsolidated Joint Venture	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investment in Unconsolidated Joint Venture	Investment in Unconsolidated Joint Venture On November 10, 2017 , the Company, the Joint Venture, BREIT LP and BREIT GP executed the Contribution Agreement whereby the Company agreed to contribute a portfolio of 20 properties owned by the Company to the Joint Venture in exchange for a combination of cash and a 10% ownership interest in the Joint Venture. BREIT LP owns a 90% interest in the Joint Venture and BREIT GP serves as the general partner of the Joint Venture. Each of BREIT LP and BREIT GP is a wholly-owned subsidiary of Blackstone Real Estate Income Trust, Inc. SIR LANDS Holdings, LLC, a newly formed wholly-owned subsidiary of the Company, holds the Company’s 10% interest in the Joint Venture. The Company exercises significant influence, but does not control the Joint Venture. Accordingly, as of the First Closing Date, the Company deconsolidated the First Closing Properties and has accounted for its investment in the Joint Venture under the equity method of accounting. Income, losses, contributions and distributions are generally allocated based on the members’ respective equity interests. As of December 31, 2017 , the book value of the Company’s investment in the Joint Venture was $8,133,156 , which includes $5,515,754 of outside basis difference. During the year ended December 31, 2017 , $106,519 of amortization of this basis difference was included in equity in loss from unconsolidated joint venture on the accompanying consolidated statements of operations. During the year ended December 31, 2017 , the Company did not receive any distributions related to its investment in the Joint Venture. Summarized financial information for the Joint Venture is: December 31, 2017 Assets: Real estate assets, net $ 374,277,205 Other assets 15,328,440 Total assets $ 389,605,645 Liabilities and equity: Notes payable, net $ 264,558,057 Other liabilities 11,525,292 Company’s capital 11,352,230 Other partner’s capital 102,170,066 Total liabilities and equity $ 389,605,645 For the Period from November 15, 2017 to December 31, 2017 Revenues $ 5,756,455 Expenses 11,330,228 Net loss $ (5,573,773 ) Company’s proportional net loss $ (557,377 ) Amortization of outside basis (106,519 ) Equity in loss of unconsolidated joint venture $ (663,896 )

Other Assets

Other Assets	12 Months Ended
	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets, Net	Other Assets As of December 31, 2017 and 2016 , other assets consisted of: December 31, 2017 2016 Prepaid expenses $ 2,132,212 $ 3,041,353 Interest rate cap agreements (Note 12) 51,646 618,841 Deposits 1,074,726 1,126,568 Other assets $ 3,258,584 $ 4,786,762

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt Mortgage Notes Payable The following is a summary of mortgage notes payable, net secured by real property as of December 31, 2017 and 2016 : December 31, 2017 Interest Rate Range Weighted Average Interest Rate Type Number of Instruments Maturity Date Range Minimum Maximum Principal Outstanding Mortgage notes payable - fixed 32 4/1/2018 - 10/1/2056 3.19 % 5.75 % 3.89 % $ 416,673,854 Mortgage notes payable - variable (1) 14 10/1/2018 - 1/1/2026 1-Mo LIBOR + 2.02% 1-Mo LIBOR + 2.50% 3.86 % 372,481,000 Total mortgage notes payable, gross 46 3.87 % 789,154,854 Premium, net (2) 673,653 Deferred financing costs, net (3) (4,264,667 ) Total mortgage notes payable, net $ 785,563,840 December 31, 2016 Interest Rate Range Weighted Average Interest Rate Type Number of Instruments Maturity Date Range Minimum Maximum Principal Outstanding Mortgage notes payable - fixed 37 10/1/2017 - 10/1/2056 3.19 % 5.94 % 4.06 % $ 471,344,145 Mortgage notes payable - variable (1) 21 8/31/2017 - 1/1/2026 1-Mo LIBOR + 1.65% 1-Mo LIBOR + 2.65% 3.05 % 517,885,675 Total mortgage notes payable, gross 58 3.52 % 989,229,820 Premium/discount, net (2) 2,208,619 Deferred financing costs, net (3) (6,358,285 ) Total mortgage notes payable, net $ 985,080,154 _______________ (1) See Note 12 for a discussion of the interest rate cap agreements used to manage the exposure to interest rate movement on the Company’s variable rate loans. (2) The following table summarizes the debt premiums as of December 31, 2017 , including the unamortized portion included in the principal balance as well as amounts amortized as an offset to interest expense in the accompanying consolidated statements of operations: Unamortized Portion of Net Debt Premium as of December 31, 2017 Amortization of Net Debt Premium During the Years Ended December 31, 2017 2016 2015 $ 673,653 $ 1,129,960 $ 1,243,385 $ 1,234,793 (3) The following table summarizes the deferred financing costs, net related to mortgage notes payable as of December 31, 2017 and 2016 : December 31, 2017 2016 Deferred financing costs $ 8,215,716 $ 10,104,244 Less: accumulated amortization (3,951,049 ) (3,745,959 ) Deferred financing costs, net $ 4,264,667 $ 6,358,285 Refinancing Transactions On June 29 and June 30, 2016 , 14 wholly-owned subsidiaries of the Company terminated the existing mortgage loans with their respective lenders for an aggregate principal amount of $283,313,677 and entered into new loan agreements (each a “Loan Agreement”) with, as applicable, PNC Bank, National Association (“PNC Bank”), and Berkeley Point Capital LLC (“Berkeley” and, together with PNC Bank, the “Lenders”) for an aggregate principal amount of $358,002,000 (the “June Refinancing Transactions”). On July 29, 2016 , nine wholly-owned subsidiaries of the Company also entered into a credit agreement (the “Credit Agreement”) with PNC Bank in connection with the refinancing of certain additional mortgage loans as further detailed below. Further, on August 30, 2016 and September 29, 2016 , three wholly-owned subsidiaries of the Company terminated the existing mortgage loans with an aggregate principal amount of $61,575,025 and entered into new mortgage notes for an aggregate principal amount of $63,620,600 (together with the June Refinancing Transactions, the “Refinancing Transactions”). In the June Refinancing Transactions, each Loan Agreement was made pursuant to the Freddie Mac Capital Markets Execution Program (“CME”), as evidenced by a multifamily note. Pursuant to the CME, the applicable Lender originates the mortgage loan and then transfers the loan to the Federal Home Loan Mortgage Association. Each Loan Agreement provides for a term loan with a maturity date of July 1, 2023 , unless the maturity date is accelerated in accordance with the terms of the loan. Each loan accrues interest at the one-month London Interbank Offered Rate (“LIBOR”) plus 2.31% . Interest and principal payments on the loans are payable monthly in arrears on specified dates as set forth in each Loan Agreement. Monthly payments are due and payable on the first day of each month, commencing August 1, 2016 . Revolving Credit Facility The Company entered into a revolving credit facility with PNC Bank to borrow up to $20,000,000 . On July 18, 2014 , the Company and PNC Bank amended the revolving credit facility to, among other things, increase the potential borrowing limit from $20,000,000 to $35,000,000 . The amended and restated credit facility consisted of a Tranche A and a Tranche B, and provided certain security for borrowings under the credit facility. The maximum amounts that could be borrowed under Tranche A and Tranche B were $20,000,000 and $15,000,000 , respectively. For each advance under the amended and restated revolving credit facility, the Company had the option to select the interest rate from the following options: (1) Base Rate Option (as defined in the amended and restated credit facility) plus (i) with respect to Tranche A, 0.75% and (ii) with respect to Tranche B, 2.0% ; or (2) LIBOR Option, which was a rate per annum fixed for the LIBOR Interest Period (as defined in the amended and restated credit facility) equal to the sum of LIBOR plus (i) with respect to Tranche A, 1.6% and (ii) with respect to Tranche B, 3.0% . The Company elected for each draw the LIBOR Option. Additionally, the Company incurred a commitment fee equal to 0.25% of the average daily difference between the $35,000,000 maximum available balance and the aggregate outstanding principal balance. No amounts were outstanding under the revolving credit facility as of December 31, 2017 or December 31, 2016 . The amended and restated revolving credit facility had a maturity date of July 17, 2016 , subject to extension. On June 30, 2016 , the Company repaid all outstanding amounts due and terminated the amended and restated revolving credit facility. Credit Facility On July 29, 2016, nine wholly-owned subsidiaries of the Company entered into the Credit Agreement and a multifamily note with PNC Bank (the Credit Agreement, multifamily note, loan and security agreements, mortgages and guaranty, collectively referred to herein as the “Loan Documents”) that provide for a new credit facility in an amount not to exceed $350,000,000 to refinance certain of the Company’s existing mortgage loans. The credit facility has a maturity date of August 1, 2021 , subject to extension, as further described in the Credit Agreement. Advances made under the credit facility are secured by the properties set out in the table below (the “Collateral Pool Property”), pursuant to a mortgage deed of trust with the nine wholly-owned subsidiaries of the Company in favor of PNC Bank. The credit facility accrues interest at the one-month LIBOR plus (1) the servicing spread of 0.05% and (2) the net spread, based on the debt service coverage ratio, of between 1.73% and 1.93% , as further described in the Credit Agreement. Interest only payments on the credit facility are payable monthly in arrears and are due and payable on the first day of each month, commencing September 1, 2016. The entire outstanding principal balance and any accrued and unpaid interest on the credit facility are due on the maturity date. The Company’s nine wholly-owned subsidiaries may voluntarily prepay all or a portion of the amounts advanced under the Loan Documents. Notwithstanding the foregoing, in the event a Collateral Pool Property is released or the Credit Agreement is terminated, a termination fee is due and payable by the Company’s nine wholly-owned subsidiaries. In certain instances of a breach of the Credit Agreement, the Company guarantees to PNC Bank the full and prompt payment and performance when due of all amounts for which the Company’s nine wholly-owned subsidiaries are personally liable under the Loan Documents, in addition to all costs and expenses incurred by PNC Bank in enforcing such guaranty. The Company paid loan origination fees to PNC Bank of $1,293,186 , and the Advisor earned a refinancing fee of $1,175,624 . As of December 31, 2017 and 2016 , the advances obtained under the credit facility on July 29, 2016 are summarized in the following table: Amount of Advance as of December 31, Collateralized Property (1) 2017 2016 Ashley Oaks Apartment Homes (2) $ — $ 24,867,500 Trails at Buda Ranch (2) — 21,025,000 Deer Valley Apartments (2) — 22,982,500 Carrington Park at Huffmeister 20,430,500 20,430,500 Carrington Place 27,535,500 27,535,500 Carrington at Champion Forest 25,121,250 25,121,250 Audubon Park Apartments (2) — 16,602,500 Oak Crossing 17,980,000 17,980,000 Meritage at Steiner Ranch (2) — 58,580,000 91,067,250 235,124,750 Deferred financing costs, net on credit facility (3) (845,152 ) (2,488,624 ) Credit facility, net $ 90,222,098 $ 232,636,126 ___________ (1) Each property is pledged as collateral for repayment of all amounts advanced under the credit facility. (2) The outstanding amount was repaid in full in conjunction with such property’s disposition during the year ended December 31, 2017 . (3) Accumulated amortization related to deferred financing costs for the credit facility as of December 31, 2017 and December 31, 2016 , was $390,241 and $433,522 , respectively. Maturity and Interest The following is a summary of the Company’s aggregate maturities as of December 31, 2017 : Maturities During the Years Ending December 31, Contractual Obligation Total 2018 2019 2020 2021 2022 Thereafter Principal payments on outstanding debt obligations (1) $ 880,222,104 $ 61,059,734 $ 100,037,883 $ 71,298,949 $ 123,518,437 $ 34,615,399 $ 489,691,702 ________________ (1) Projected principal payments on outstanding debt obligations are based on the terms of the notes payable agreements. Amounts exclude the amortization of the deferred financing costs and debt premiums associated with certain notes payable. The Company’s notes payable contain customary financial and non-financial debt covenants. As of December 31, 2017 and 2016 , the Company was in compliance with all financial and non-financial debt covenants. For the years ended December 31, 2017 , 2016 and 2015 , the Company incurred interest of $44,114,130 , $40,631,593 and $39,302,938 , respectively. Interest expense for the years ended December 31, 2017 , 2016 and 2015 , includes amortization of deferred financing costs of $1,839,952 , $1,723,186 and $1,553,718 , amortization of loan premiums and discounts of $1,129,960 , $1,243,385 and $1,234,793 , net unrealized loss ( gain ) from the change in fair value of interest rate cap agreements of $604,545 , $(61,698) and $2,032,746 , and capitalized interest of $0 , $80,166 and $153,920 , respectively. The capitalized interest is included in real estate on the consolidated balance sheets. Interest expense of $2,766,036 and $3,444,162 was payable as of December 31, 2017 and 2016 , respectively, and is included in accounts payable and accrued liabilities in the accompanying consolidated balance sheets.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity General Under the Company’s Third Articles of Amendment and Restatement (the “Charter”), the total number of shares of capital stock authorized for issuance is 1,100,000,000 shares, consisting of 999,999,000 shares of common stock with a par value of $0.01 per share, 1,000 shares of convertible stock with a par value of $0.01 per share and 100,000,000 shares designated as preferred stock with a par value of $0.01 per share. Common Stock The shares of the Company’s common stock entitle the holders to one vote per share on all matters upon which stockholders are entitled to vote, to receive dividends and other distributions as authorized by the Company’s board of directors in accordance with the Maryland General Corporation Law and to all rights of a stockholder pursuant to the Maryland General Corporation Law. The common stock has no preferences or preemptive, conversion or exchange rights. During 2009, the Company issued 22,223 shares of common stock to the Sponsor for $200,007 . From inception to December 31, 2017 , the Company had issued 76,732,395 shares of common stock in its Private Offering and Public Offering for offering proceeds of $679,572,220 , net of offering costs of $95,845,468 , including 4,073,759 shares of common stock pursuant to the DRP, for total proceeds of $39,580,847 . Offering costs primarily consisted of selling commissions and dealer manager fees. The Company terminated its Public Offering on December 20, 2013, but continued to offer shares pursuant to the DRP through November 30, 2014. The issuance and vesting activity for the years ended December 31, 2017 , 2016 and 2015 , for the restricted stock issued to the Company’s independent directors as compensation for services in connection with their initial election or re-election to the board of directors at the Company’s annual meeting, upon their departure from the board of directors, or in appreciation of their service and commitment to the Company is as follows: 2017 2016 2015 Nonvested shares at the beginning of the year 11,875 11,250 16,875 Granted shares 7,500 7,500 14,000 Vested shares (7,500 ) (6,875 ) (19,625 ) Nonvested shares at the end of the year 11,875 11,875 11,250 The weighted average fair value of restricted stock issued to the Company’s independent directors for the years ended December 31, 2017 , 2016 and 2015 is as follows: Grant Year Weighted Average Fair Value 2015 $ 10.35 2016 11.44 2017 11.65 The shares of restricted common stock vest and become non-forfeitable in four equal annual installments beginning on the date of grant and ending on the third anniversary of the date of grant and will become fully vested and become non-forfeitable on the earlier to occur of (1) the termination of the independent director’s service as a director due to death or disability, or (2) a change in control of the Company and as otherwise provided in the Incentive Award Plan, as defined below. Included in general and administrative expenses is $85,486 , $76,285 and $184,350 for the years ended December 31, 2017 , 2016 and 2015 , respectively, for compensation expense related to the issuance of restricted common stock. The weighted average remaining term of the restricted common stock is 1.51 years as of December 31, 2017 . As of December 31, 2017 , the compensation expense related to the issuance of the restricted common stock not vested was $107,002 . On June 11, 2014 , the Company entered into a restricted stock agreement with the Advisor whereby the Company issued to the Advisor 488,281.25 restricted shares of the Company’s common stock at a fair market value of $10.24 per share in satisfaction of certain deferred fees due to the Advisor in the aggregate amount of $5,000,000 . Pursuant to the restricted stock agreement, the shares of restricted stock vested and became non-forfeitable 50% at December 31, 2015 and 50% at December 31, 2016. The fair value of the vested common stock as of December 31, 2017 and 2016 of $5,637,207 , respectively, was recorded in stockholders’ equity in the accompanying consolidated balance sheets. Included in general and administrative expenses on the accompanying consolidated statements of operations is $0 , $312,353 and $300,440 for the years ended December 31, 2017 , 2016 and 2015 for the change in value of restricted common stock issued to the Advisor. Convertible Stock During 2009, the Company issued 1,000 shares of Convertible Stock to the Advisor for $1,000 . The Convertible Stock will convert into shares of the Company’s common stock if and when: (A) the Company has made total distributions on the then outstanding shares of common stock equal to the original issue price of those shares plus an 8.0% cumulative, non-compounded, annual return on the original issue price of those shares, (B) subject to specified conditions, the Company lists the common stock for trading on a national securities exchange or (C) the Advisory Agreement is terminated or not renewed by the Company (other than for “cause” as defined in the Advisory Agreement). A “listing” will also be deemed to have occurred on the effective date of any merger of the Company in which the consideration received by the holders of the Company’s common stock is the securities of another issuer that are listed on a national securities exchange. Upon conversion, each share of Convertible Stock will convert into a number of shares of common stock equal to 1/1000 of the quotient of (A) 10% of the amount, if any, by which (1) the Company’s “enterprise value” (as defined in the Charter) plus the aggregate value of distributions paid to date on the outstanding shares of common stock exceeds (2) the aggregate purchase price paid by the stockholders for those shares plus an 8.0% cumulative, non-compounded, annual return on the original issue price of those shares, divided by (B) the Company’s enterprise value divided by the number of outstanding shares of common stock, in each case calculated as of the date of the conversion. In the event of a termination or non-renewal of the Advisory Agreement by the Company for cause, the Convertible Stock will be redeemed by the Company for $1.00 . Preferred Stock The Charter also provides the Company’s board of directors with the authority to issue one or more classes or series of preferred stock, and prior to the issuance of such shares of preferred stock, the board of directors shall have the power from time to time to classify or reclassify, in one or more series, any unissued shares and designate the preferences, rights and privileges of such shares of preferred stock. The Company’s board of directors is authorized to amend the Charter, without the approval of the stockholders, to increase the aggregate number of authorized shares of capital stock or the number of shares of any class or series that the Company has authority to issue. As of December 31, 2017 and 2016 , no shares of the Company’s preferred stock were issued and outstanding. Distribution Reinvestment Plan The Company’s board of directors had approved the DRP through which common stockholders could elect to reinvest an amount equal to the distributions declared on their shares of common stock in additional shares of the Company’s common stock in lieu of receiving cash distributions. The initial purchase price per share under the DRP was $9.50 . Effective September 10, 2012, shares of the Company’s common stock were issued pursuant to the DRP at a price of $9.73 per share. Effective with distributions earned beginning on December 1, 2014, the Company’s board of directors elected to suspend the DRP. As a result, all distributions are paid in cash and not reinvested in shares of the Company’s common stock. The Company’s board of directors may, in its sole discretion, from time to time, reinstate the DRP, although there is no assurance as to if or when this will happen, and change the DRP price based upon changes in the Company’s estimated value per share and other factors that the Company’s board of directors deems relevant. No sales commissions or dealer manager fees were payable on shares sold through the DRP. Share Repurchase Program and Redeemable Common Stock The Company’s share repurchase program may provide an opportunity for stockholders to have their shares of common stock repurchased by the Company, subject to certain restrictions and limitations. No shares can be repurchased under the Company’s share repurchase program until after the first anniversary of the date of purchase of such shares; provided, however, that this holding period does not apply to repurchases requested within two years after the death or disability of a stockholder. The purchase price for shares repurchased under the Company’s share repurchase program is as follows: Share Purchase Anniversary Repurchase Price on Repurchase Date (1)(2) Less than 1 year No Repurchase Allowed 1 year 92.5% of Estimated Value per Share 2 years 95.0% of Estimated Value per Share 3 years 97.5% of Estimated Value per Share 4 years 100.0% of Estimated Value per Share In the event of a stockholder’s death or disability (3) Average Issue Price for Shares (4) ________________ (1) As adjusted for any stock dividends, combinations, splits, recapitalizations or any similar transaction with respect to the shares of common stock. (2) For purposes of the share repurchase program, the “Estimated Value per Share” equals the most recently determined estimated value per share determined by the Company’s board of directors. (3) The required one year holding period to be eligible to redeem shares under the Company’s share repurchase program does not apply in the event of death or disability of a stockholder. (4) The purchase price per share for shares redeemed upon the death or disability of a stockholder will be equal to the average issue price per share for all of the stockholder’s shares. The purchase price per share for shares repurchased pursuant to the share repurchase program is further reduced by the aggregate amount of net proceeds per share, if any, distributed to the Company’s stockholders prior to the repurchase date as a result of the sale of one or more of the Company’s assets that constitutes a return of capital distribution as a result of such sales. Repurchases of shares of the Company’s common stock are made quarterly upon written request to the Company at least 15 days prior to the end of the applicable quarter during which the share repurchase program is in effect. Repurchase requests are honored approximately 30 days following the end of the applicable quarter (the “Repurchase Date”). Stockholders may withdraw their repurchase request at any time up to three business days prior to the end of the applicable quarter. During the year ended December 31, 2017 , the Company redeemed a total of 730,953 shares with a total redemption value of $8,000,000 and received net requests for the redemption of 2,521,337 shares with a total net redemption value of $28,904,491 . During the year ended December 31, 2016 , the Company redeemed a total of 479,147 shares with a total redemption value of $5,000,000 and received net requests for the repurchase of 1,335,407 shares with a total net repurchase value of $14,625,190 . As of December 31, 2017 and 2016 , the Company’s total outstanding redemption requests received that were subject to the Company’s limitations on redemptions (discussed below) were 3,100,720 shares and 1,310,337 shares, respectively, with a total net redemption value of $36,198,922 and $14,709,973 , respectively. The Company cannot guarantee that the funds set aside for the share repurchase program will be sufficient to accommodate all repurchase requests made in any quarter. In the event that the redemption requests exceed the Company’s limitations on redemptions or the Company does not have sufficient funds available to repurchase all of the shares of the Company’s common stock for which repurchase requests have been submitted in any quarter, priority will be given to redemption requests in the case of the death or disability of a stockholder. If the Company repurchases less than all of the shares subject to a repurchase request in any quarter, with respect to any shares which have not been repurchased, the requesting stockholder could (1) withdraw the request for repurchase or (2) ask that the Company honor the request in a future quarter, if any, when such repurchases may be made pursuant to the limitations of the share repurchase program and when sufficient funds were available. Such pending requests will be honored among all requests for redemptions in any given redemption period as follows: first, pro rata as to redemptions sought upon a stockholder’s death or disability; and, next, pro rata as to other redemption requests. The Company is not obligated to repurchase shares of the Company’s common stock under the share repurchase program. In no event shall redemptions under the share repurchase program exceed 5% of the weighted average number of shares of the Company’s common stock outstanding during the prior calendar year. Effective July 1, 2015, the Company’s board of directors determined to limit the amount of shares repurchased pursuant to the share repurchase program to an amount not to exceed $2,000,000 during the quarter beginning July 1, 2015, with each subsequent quarter not to exceed $1,000,000 . On August 9, 2016, the Company’s board of directors approved and authorized an increase to the value of the shares that may be repurchased pursuant to the share repurchase program from $1,000,000 to $2,000,000 per quarter, effective on the October 2016 repurchase date. There is no fee in connection with a repurchase of shares of the Company’s common stock. As of December 31, 2017 , the Company has recognized redemptions payable of $2,000,000 , which is included in accounts payable and accrued liabilities on the accompanying consolidated balance sheets. The Company’s board of directors may, in its sole discretion, amend, suspend, or terminate the share repurchase program at any time upon 30 days’ notice to the Company’s stockholders if it determines that the funds available to fund the share repurchase program are needed for other business or operational purposes or that amendment, suspension or termination of the share repurchase program is in the best interest of the Company’s stockholders. Therefore, stockholders may not have the opportunity to make a repurchase request prior to any potential termination of the Company’s share repurchase program. Distributions Declared Distributions declared during 2017 (1) accrued daily to stockholders of record as of the close of business on each day, (2) were payable in cumulative amounts on or before the third day of each calendar month with respect to the prior month and (3) were calculated at a rate of $0.001964 per share per day, which if paid each day over a 365-day period is equivalent to a 7.0% annualized distribution rate based on a purchase price of $10.24 per share of common stock. Distributions declared for the years ended December 31, 2017 and 2016 , were $54,339,823 and $54,828,267 , all of which were attributable to cash distributions. As of December 31, 2017 and 2016 , $4,595,301 and $4,625,355 distributions declared were payable. Distributions Paid For the years ended December 31, 2017 and 2016 , the Company paid cash distributions of $54,369,877 and $54,871,173 , which related to distributions declared for each day in the period from December 1, 2016 through November 30, 2017 and December 1, 2015 through November 30, 2016 , respectively. All such distributions were paid in cash.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings (Loss) Per Share The following table presents a reconciliation of net loss attributable to common stockholders and shares used in calculating basic and diluted earnings (loss) per share, (“EPS”), for the years ended December 31, 2017 , 2016 and 2015 : Years Ended December 31, 2017 2016 2015 Net income (loss) attributable to the Company $ 72,473,867 $ (25,579,651 ) $ (13,024,358 ) Less: dividends declared on participating securities 9,323 183,805 360,446 Net income (loss) attributable to common stockholders 72,464,544 (25,763,456 ) (13,384,804 ) Weighted average common shares outstanding — basic 75,794,705 76,195,083 76,335,114 Weighted average common shares outstanding — diluted 75,807,710 76,195,083 76,335,114 Earnings (loss) per common share — basic and diluted $ 0.96 $ (0.34 ) $ (0.18 ) For the years ended December 31, 2016 and 2015 , the Company excluded all unvested restricted common shares outstanding issued to the Advisor and the Company’s independent directors from the calculation of diluted loss per common share as the effect would have been antidilutive.

Related Party Arrangements

Related Party Arrangements	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Arrangements	Related Party Arrangements The Company has entered into the Advisory Agreement with the Advisor. Pursuant to the Advisory Agreement, the Company is obligated to pay the Advisor specified fees upon the provision of certain services related to the investment of funds in real estate and real estate-related investments, the management of the Company’s investments and for other services (including, but not limited to, the disposition of investments). Subject to the limitations described below, the Company is also obligated to reimburse the Advisor and its affiliates for organization and offering costs incurred by the Advisor and its affiliates on behalf of the Company, and the Company is obligated to reimburse the Advisor and its affiliates for acquisition and origination expenses and certain operating expenses incurred on behalf of the Company or incurred in connection with providing services to the Company. Amounts attributable to the Advisor and its affiliates incurred (received) for the years ended December 31, 2017 , 2016 and 2015 are as follows: Incurred (Received) For the Year Ended December 31, 2017 2016 2015 Consolidated Statements of Operations: Expensed Investment management fees (1) $ 13,823,000 $ 14,075,818 $ 13,854,825 Acquisition fees (1) — 960 187,735 Acquisition expenses (2) — — 7,145 Property management Fees (1) 6,278,850 6,406,479 6,188,525 Reimbursement of onsite personnel (3) 18,716,284 18,751,492 18,760,621 Other fees (1) 1,771,620 1,673,724 1,696,828 Other fees - property operations (3) 170,067 — — Other fees - G&A (4) 133,419 168,037 — Other operating expenses (4) 1,244,264 1,232,493 1,346,002 Disposition fees (5) 6,706,200 — — Disposition transaction costs (5) 56,922 — — Refinancing fee (1) 86,675 3,283,737 — Property insurance (6) 1,285,490 311,794 172,769 Insurance proceeds (7) (102,147 ) (113,853 ) — Consolidated Balance Sheets: Capitalized Construction management Fees (8) 526,866 1,493,999 1,618,438 Reimbursement of labor costs (8) 239,015 367,204 233,748 Capital expenditures (8) 74,709 17,654 3,900 Deferred financing costs (9) 12,930 139,229 — Capitalized costs on investment in unconsolidated joint venture (10) 65,113 — — Acquisition expenses 3,226 — — $ 51,092,503 $ 47,808,767 $ 44,070,536 ________________ (1) Included in fees to affiliates in the accompanying consolidated statements of operations. (2) Included in acquisition costs in the accompanying consolidated statements of operations. (3) Included in operating, maintenance and management in the accompanying consolidated statements of operations. (4) Included in general and administrative expenses in the accompanying consolidated statements of operations. (5) Included in gain on sales of real estate, net in the accompanying consolidated statements of operations. (6) Property related insurance expense and the amortization of the prepaid insurance deductible account are included in general and administrative expenses in the accompanying consolidated statements of operations. The amortization of the prepaid property insurance is included in operating, maintenance and management expenses in the accompanying consolidated statements of operations. The prepaid insurance is included in other assets in the accompanying consolidated balance sheets upon payment. (7) Included in tenant reimbursements and other in the accompanying consolidated statements of operations. (8) Included in building and improvements in the accompanying consolidated balance sheets. (9) Included in mortgage notes payable, net in the accompanying consolidated balance sheets. (10) Included in investment in unconsolidated joint venture in the accompanying consolidated balance sheets. Amounts attributable to the Advisor and its affiliates paid (received) for the years ended December 31, 2017 , 2016 and 2015 are as follows: Paid (Received) For the Year Ended December 31, 2017 2016 2015 Consolidated Statements of Operations: Expensed Investment management fees $ 15,008,001 $ 14,060,587 $ 13,840,067 Acquisition fees — 960 791,135 Acquisition expenses — — 11,147 Property management Fees 6,410,591 6,392,550 6,169,938 Reimbursement of onsite personnel 18,748,974 18,650,009 18,639,991 Other fees 1,781,318 1,671,282 1,721,504 Other fees - property operations 170,067 — — Other fees - G&A 133,419 168,037 — Other operating expenses 1,341,997 1,098,568 1,367,226 Disposition fees 6,139,575 — — Disposition transaction costs 56,922 — — Refinancing fee — 3,283,737 — Property insurance 1,322,247 361,490 247,258 Insurance proceeds (102,147 ) (113,853 ) — Consolidated Balance Sheets: Capitalized Construction management Fees 536,866 1,548,701 1,590,514 Reimbursement of labor costs 245,889 474,155 119,626 Capital expenditures 74,709 17,654 3,900 Deferred financing costs 12,930 139,229 — Capitalized costs on investment in unconsolidated joint venture 65,113 — — Acquisition expenses 3,226 — — $ 51,949,697 $ 47,753,106 $ 44,502,306 Amounts attributable to the Advisor and its affiliates that are payable (prepaid) as of December 31, 2017 and 2016 are as follows: Payable (Prepaid) as of December 31, 2017 2016 Consolidated Statements of Operations: Expensed Investment management fees $ — $ 1,185,001 Acquisition fees — — Acquisition expenses — — Property management Fees 402,315 534,056 Reimbursement of onsite personnel 772,584 805,274 Other fees 44,981 54,679 Other fees - property operations — — Other fees - G&A — — Other operating expenses 87,221 184,954 Disposition fees 566,625 — Disposition transaction costs — — Refinancing fee 86,675 — Property insurance (160,942 ) (124,185 ) Insurance proceeds — — Consolidated Balance Sheets: Capitalized Construction management Fees 6,431 16,431 Reimbursement of labor costs 297 7,171 Capital expenditures — — Deferred financing costs — — Capitalized costs on investment in unconsolidated joint venture — — Acquisition expenses — — $ 1,806,187 $ 2,663,381 Investment Management Fee The Company pays the Advisor a monthly investment management fee equal to one-twelfth of 0.80% of (1) the cost of real properties and real estate-related assets acquired directly by the Company or (2) the Company’s allocable cost of each real property or real estate-related asset acquired through a joint venture. The investment management fee is calculated including acquisition fees, acquisition expenses and any debt attributable to such investments, or the Company’s proportionate share thereof in the case of investments made through joint ventures. The cost of real properties and real estate-related assets that have been sold by the Company during the applicable month is excluded from the fee. Acquisition Fees and Expenses The Company pays the Advisor an acquisition fee equal to 2.0% of (1) the cost of investment, as defined in the Advisory Agreement, in connection with the acquisition or origination of any type of real property or real estate-related asset acquired directly by the Company or (2) the Company’s allocable portion of the purchase price in connection with the acquisition or origination of any type of real property or real estate-related asset acquired through a joint venture, including any acquisition and origination expenses and any debt attributable to such investments. In addition to acquisition fees, the Company reimburses the Advisor for amounts directly incurred by the Advisor or its affiliates, including personnel-related costs for acquisition due diligence, legal and non-recurring management services, and amounts the Advisor pays to third parties in connection with the selection, acquisition or development of a property or acquisition of real estate-related assets, whether or not the Company ultimately acquires the property or the real estate-related assets. The Charter limits the Company’s ability to pay acquisition fees if the total of all acquisition fees and expenses relating to the purchase would exceed 6.0% of the contract purchase price. Under the Charter, a majority of the Company’s board of directors, including a majority of the independent directors, is required to approve any acquisition fees (or portion thereof) that would cause the total of all acquisition fees and expenses relating to an acquisition to exceed 6.0% of the contract purchase price. In connection with the purchase of securities, the acquisition fee may be paid to an affiliate of the Advisor that is registered as a FINRA member broker-dealer if applicable FINRA rules would prohibit the payment of the acquisition fee to a firm that is not a registered broker-dealer. Property Management Fees and Expenses The Company has entered into Property Management Agreements with Steadfast Management Company, Inc., an affiliate of the Sponsor (the “Property Manager”), in connection with the acquisition of each of the Company’s properties (other than EBT Lofts, Library Lofts and Stuart Hall Lofts, which are managed by an unaffiliated third-party management company). The property management fee payable with respect to each property under the Property Management Agreements (each a “Property Management Agreement”) ranges from 2.50% to 3.75% of the annual gross revenue collected, which is usual and customary for comparable property management services rendered to similar properties in similar geographic markets, as determined by the Advisor and approved by a majority of the members of the Company’s board of directors, including a majority of the independent directors. The Property Manager also receives an oversight fee of 1% of gross revenues at certain of the properties at which it does not serve as a property manager. Generally, each Property Management Agreement has an initial one year term and will continue thereafter on a month-to-month basis unless either party gives a 60 day prior notice of its desire to terminate the Property Management Agreement, provided that the Company may terminate the Property Management Agreement at any time upon a determination of gross negligence, willful misconduct or bad acts of the Property Manager or its employees or upon an uncured breach of the Property Management Agreement upon 30 days’ prior written notice to the Property Manager. In addition to the property management fee, the Property Management Agreements also specify certain other fees payable to the Property Manager or its affiliates, including fees for benefit administration, information technology infrastructure, licenses, and support and training services. The Company also reimburses the Property Manager for the salaries and related benefits of on-site property management employees. Construction Management The Company has entered into Construction Management Agreements with Pacific Coast Land and Construction, Inc., an affiliate of the Sponsor (the “Construction Manager”), in connection with the planned capital improvements and renovation for certain of the Company’s properties. The construction management fee payable with respect to each property under the Construction Management Agreements (each a “Construction Management Agreement”) ranges from 5.0% to 12.0% of the costs of the improvements for which the Construction Manager has planning and oversight authority. Generally, each Construction Management Agreement can be terminated by either party with a 30 days’ prior written notice to the other party. Construction management fees are capitalized to the respective real estate properties in the period in which they are incurred, as such costs relate to capital improvements and renovations for units taken out of service while they undergo the planned renovation. The Company may also reimburse the Construction Manager for the salaries and related benefits of certain of its employees for time spent working on capital improvements and renovations at its properties. Property Insurance The Company deposits amounts with an affiliate of the Sponsor to fund a prepaid insurance deductible account to cover the cost of required insurance deductibles across all properties of the Company and other affiliated entities. Upon filing a major claim, proceeds from the insurance deductible account may be used by the Company or another affiliate of the Sponsor. In addition, the Company deposits amounts with an affiliate of the Sponsor to cover the cost of property insurance across certain properties of the Company. Capital Expenditures The Company reimburses an affiliate of the Sponsor for capital expenditures incurred by the Company’s multifamily properties. Other Operating Expense Reimbursement In addition to the various fees paid to the Advisor, the Company is obligated to pay directly or reimburse all expenses incurred by the Advisor in providing services to the Company, including the Company’s allocable share of the Advisor’s overhead, such as rent, employee costs, utilities and information technology costs. The Company will not reimburse the Advisor for employee costs in connection with services for which the Advisor or its affiliates receive acquisition fees or disposition fees or for the salaries the Advisor pays to the Company’s executive officers. The Charter limits the Company’s total operating expenses during any four fiscal quarters to the greater of 2% of the Company’s average invested assets or 25% of the Company’s net income for the same period (the “ 2% / 25% Limitation”). The Company may reimburse the Advisor, at the end of each fiscal quarter, for operating expenses incurred by the Advisor; provided, however, that the Company shall not reimburse the Advisor at the end of any fiscal quarter for operating expenses that exceed the 2%/25% Limitation unless the independent directors have determined that such excess expenses were justified based on unusual and non-recurring factors. The Advisor must reimburse the Company for the amount by which the Company’s operating expenses for the preceding four fiscal quarters then ended exceed the 2% / 25% Limitation unless the independent directors have determined that such excess expenses were justified. For purposes of determining the 2% / 25% Limitation amount, “average invested assets” means the average monthly book value of the Company’s assets invested directly or indirectly in equity interests and loans secured by real estate during the 12 -month period before deducting depreciation, bad debts or other non-cash reserves. “Total operating expenses” means all expenses paid or incurred by the Company that are in any way related to the Company’s operation, including the Company’s allocable share of Advisor overhead and investment management fees, but excluding (a) the expenses of raising capital such as organization and offering expenses, legal, audit, accounting, underwriting, brokerage, listing, registration and other fees, printing and other such expenses and taxes incurred in connection with the issuance, distribution, transfer, listing and registration of shares of the Company’s common stock; (b) interest payments; (c) taxes; (d) non-cash expenditures such as depreciation, amortization and bad debt reserves; (e) reasonable incentive fees based on the gain in the sale of the Company’s assets; (f) acquisition fees and acquisition expenses (including expenses relating to potential acquisitions that the Company does not close); (g) real estate commissions on the resale of investments; and (h) other expenses connected with the acquisition, disposition, management and ownership of investments (including the costs of foreclosure, insurance premiums, legal services, maintenance, repair and improvement of real property). For the year ended December 31, 2017 , the Advisor and its affiliates incurred $1,244,264 of the Company’s operating expenses, including the allocable share of the Advisor’s overhead expenses of $1,244,264 , none of which were in excess of the 2%/25% Limitation and are included in the $6,732,330 of general and administrative expenses recognized by the Company. As of December 31, 2017 , the Company’s total operating expenses were 0.1% of its average invested assets and 1.7% of its net loss. For the year ended December 31, 2016 , the Advisor and its affiliates incurred $1,232,493 of the Company’s operating expenses, including the allocable share of the Advisor’s overhead expenses of $1,232,493 , none of which were in excess of the 2%/25% Limitation and are included in the $9,039,171 of general and administrative expenses recognized by the Company. For the year ended December 31, 2015 , the Advisor and its affiliates incurred $1,346,002 of the Company’s operating expenses, including the allocable share of the Advisor’s overhead expenses of $1,346,002 , none of which were in excess of the 2%/25% Limitation, and are included in the $5,949,993 of general and administrative expenses recognized by the Company. Disposition Fee The Company pays the Advisor a disposition fee in connection with a sale of a property or real estate-related asset and in the event of the sale of the entire Company (a “Final Liquidity Event”), in either case when the Advisor or its affiliates provides a substantial amount of services as determined by a majority of the Company’s independent directors. With respect to a sale of a property or real estate-related asset, the Company pays the Advisor a disposition fee equal to 1.5% of the contract sales price of the investment sold. With respect to a Final Liquidity Event, the Company will pay the Advisor a disposition fee equal to (i) 0.5% of the total consideration paid in a Final Liquidity Event if the price per share paid to stockholders is less than or equal to $9.00 ; (ii) 0.75% of the total consideration paid in a Final Liquidity Event if the price per share paid to stockholders is between $9.01 and $10.24 ; (iii) 1.00% of the total consideration paid in a Final Liquidity Event if the price per share paid to stockholders is between $10.25 and $11.24 ; (iv) 1.25% of the total consideration paid in a Final Liquidity Event if the price per share paid to stockholders is between $11.25 and $12.00 ; and (v) 1.50% of the total consideration paid in a Final Liquidity Event if the price per share paid to stockholders is greater than or equal to $12.01 . To the extent the disposition fee is paid upon the sale of any assets other than real property, it will be included as an operating expense for purposes of the 2% / 25% Limitation. In connection with the sale of securities, the disposition fee may be paid to an affiliate of the Advisor that is registered as a FINRA member broker-dealer if applicable FINRA rules would prohibit the payment of the disposition fee to a firm that is not a registered broker-dealer. The Charter limits the maximum amount of the disposition fees payable to the Advisor for the sale of any real property to the lesser of one-half of the brokerage commission paid or 3% of the contract sales price, but in no event shall the total real estate commissions paid, including any disposition fees payable to the Advisor, exceed 6% of the contract sales price. Refinancing Fee The Company paid the Advisor a refinancing fee equal to 0.50% of the refinancing amount in connection with the refinancing of certain of the Company’s existing mortgage loans. Additionally, in connection with the Refinancing Transactions, the Company reimbursed certain deferred financing costs payable to an affiliate of the Sponsor that have been recorded to notes payable, net on the accompanying consolidated balance sheets. Restricted Stock Agreement On June 11, 2014 , the Company entered into a restricted stock agreement with the Advisor whereby the Company issued to the Advisor 488,281.25 restricted shares of the Company’s common stock at a fair market value of $10.24 per share in satisfaction of certain deferred fees due to the Advisor in the aggregate amount of $5,000,000 . Pursuant to the terms of the restricted stock agreement, the shares of restricted stock vested and became non-forfeitable 50% at December 31, 2015 and 50% at December 31, 2016. Contribution, Settlement and Release Agreements Certain of the Company’s subsidiaries and the Property Manager were named as defendants in two Texas class action lawsuits alleging violations of the Texas Water Code (collectively, the “Actions”). The Company’s subsidiaries and the Property Manager disputed plaintiffs’ claims in the Actions; however, to avoid the time and expense associated with defending the Actions, the Company’s subsidiaries and other affiliated Steadfast entities (collectively, the “Steadfast Parties”) entered into Settlement Agreements with the plaintiffs that provided for a settlement payment to the class members and a release of claims by plaintiffs and class members against the Steadfast Parties. In connection with the settlement agreements, on April 17, 2017, the Steadfast Parties entered into a contribution, settlement and release agreement whereby all agreed to an allocation of all costs related to the actions and their settlements and a release of all claims a Steadfast Party may have against any other Steadfast Party. The Company’s proportionate share of the settlements was $378,405 , which consisted of funds used to pay a portion of (1) the settlement payments to the plaintiffs and class members in the actions and (2) legal costs, less insurance proceeds. During the year ended December 31, 2017, the Company had recorded $350,851 as reimbursement for funds spent by the Company in excess of its proportionate share, all of which was collected from other Steadfast Parties as of December 31, 2017.

Incentive Award Plan and Indepe

Incentive Award Plan and Independent Director Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Incentive Award Plan and Independent Director Compensation	Incentive Award Plan and Independent Director Compensation The Company has adopted an incentive plan (the “Incentive Award Plan”) that provides for the grant of equity awards to its employees, directors and consultants and those of the Company’s affiliates. The Incentive Award Plan authorizes the grant of non-qualified and incentive stock options, restricted stock awards, restricted stock units, stock appreciation rights, dividend equivalents and other stock-based awards or cash-based awards. No awards have been granted under the Incentive Award Plan as of December 31, 2017 , except those awards granted to the independent directors as described below. Under the Company’s independent directors’ compensation plan, which is a sub-plan of the Incentive Award Plan, each of the Company’s then independent directors was entitled to receive 5,000 shares of restricted common stock in connection with the initial meeting of the Company’s full board of directors. Each subsequent independent director that joins the Company’s board of directors receives 5,000 shares of restricted common stock upon election to the Company’s board of directors. The Company’s initial board of directors, including each of the independent directors, agreed to delay the initial grant of restricted stock until the Company raised $2,000,000 in gross offering proceeds in the Private Offering. In addition, on the date following an independent director’s re-election to the Company’s board of directors, he or she receives 2,500 shares of restricted common stock. One-fourth of the shares of restricted common stock generally vest and become non-forfeitable upon issuance and the remaining portion will vest in three equal annual installments beginning on the first anniversary of the date of grant and ending on the third anniversary of the date of grant; provided, however, that the restricted stock will become fully vested and become non-forfeitable on the earlier to occur of (1) the termination of the independent director’s service as a director due to his or her death or disability, or (2) a change in control of the Company and as otherwise provided in the Incentive Award Plan. On August 10, 2015, the Company’s board of directors granted 2,000 shares of restricted common stock pursuant to the Incentive Award Plan to each of Larry H. Dale and Kerry D. Vandell in appreciation of their service as independent directors and commitment to the Company for their prior years of service as independent directors, all of which vested immediately. On August 11, 2015, the Company granted each of the two then independent directors 2,500 shares of restricted common stock upon re-election to the Company’s board of directors. On August 11, 2015, the Company granted 5,000 shares of restricted common stock to Don B. Saulic, its new independent director. On August 9, 2016 , the Company granted 2,500 shares of restricted common stock to each of its three independent directors upon their re-election to the Company’s board of directors at the 2016 annual meeting of stockholders. On August 8, 2017 , the Company granted 2,500 shares of restricted common stock to each of its three independent directors upon their re-election to the Company’s board of directors at the 2017 annual meeting of stockholders. The Company recorded stock-based compensation expense of $85,486 , $76,285 and $184,350 for the years ended December 31, 2017 , 2016 and 2015 respectively.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Economic Dependency The Company is dependent on the Advisor and its affiliates for certain services that are essential to the Company, including the identification, evaluation, negotiation, purchase and disposition of real estate and real estate-related investments; management of the daily operations of the Company’s real estate and real estate-related investment portfolio; and other general and administrative responsibilities. In the event that these companies are unable to provide the respective services, the Company will be required to obtain such services from other sources. Concentration of Credit Risk The geographic concentration of the Company’s portfolio makes it particularly susceptible to adverse economic developments in the Houston, Texas apartment market. Any adverse economic or real estate developments in these markets, such as business layoffs or downsizing, relocations of businesses, increased competition from other apartment communities, decrease in demand for apartments or any other changes, could adversely affect the Company’s operating results and its ability to make distributions to stockholders. Environmental As an owner of real estate, the Company is subject to various environmental laws of federal, state and local governments. The Company is not aware of any environmental liability that could have a material adverse effect on its financial condition or results of operations. However, changes in applicable environmental laws and regulations, the uses and conditions of properties in the vicinity of the Company’s properties, the activities of its tenants and other environmental conditions of which the Company is unaware with respect to the properties could result in future environmental liabilities. Legal Matters From time to time, the Company is subject, or party, to legal proceedings that arise in the ordinary course of its business. Management is not aware of any legal proceedings of which the outcome is reasonably likely to have a material adverse effect on the Company’s results of operations or financial condition nor is the Company aware of any such legal proceedings contemplated by government agencies.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Company uses interest rate derivatives with the objective of managing exposure to interest rate movements thereby minimizing the effect of interest rate changes and the effect they could have on future cash flows. Interest rate cap agreements are used to accomplish this objective. The following table provides the terms of the Company’s interest rate derivative instruments that were in effect at December 31, 2017 and 2016 : December 31, 2017 Type Maturity Date Range Based on Number of Instruments Notional Amount Variable Rate Weighted Average Rate Cap Fair Value Interest rate cap 1/1/2018 - 10/1/2019 One-Month LIBOR 18 $ 458,655,000 1.56 % 2.89 % $ 51,646 December 31, 2016 Type Maturity Date Range Based on Number of Instruments Notional Amount Variable Rate Weighted Average Rate Cap Fair Value Interest rate cap 4/1/2017 - 10/1/2019 One-Month LIBOR 43 $ 973,400,000 0.77 % 2.70 % $ 618,841 The interest rate cap agreements are not designated as cash flow hedges. Accordingly, the Company records any changes in the fair value of the interest rate cap agreements as interest expense. The change in the fair value of the interest rate cap agreements for the years ended December 31, 2017 , 2016 and 2015 resulted in an unrealized ( loss ) gain of $(604,545) , $61,698 and $(2,032,746) , respectively, which is included in interest expense in the accompanying consolidated statements of operations. During the years ended December 31, 2017 and 2016 , the Company acquired interest rate cap agreements of $37,350 and $259,000 . The fair value of interest rate cap agreements of $51,646 and $618,841 are included in other assets on the accompanying consolidated balance sheets.

Selected Quarterly Results (una

Selected Quarterly Results (unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Results (unaudited)	Selected Quarterly Results (unaudited) Presented below is a summary of the Company’s unaudited quarterly financial information for the years ended December 31, 2017 and 2016 : First Quarter Second Quarter Third Quarter Fourth Quarter Total 2017 Revenues $ 54,280,265 $ 55,118,406 $ 55,592,107 $ 47,978,462 $ 212,969,240 Net (loss) income (5,644,875 ) (5,656,573 ) (2,326,578 ) 86,101,893 72,473,867 (Loss) income per common share, basic and diluted (0.07 ) (0.07 ) (0.03 ) 1.14 0.96 Distributions declared per common share 0.177 0.179 0.181 0.181 0.718 2016 Revenues $ 52,906,908 $ 54,022,623 $ 56,371,925 $ 54,936,076 $ 218,237,532 Net loss (3,618,142 ) (8,039,220 ) (9,699,187 ) (4,223,102 ) (25,579,651 ) Loss per common share, basic and diluted (0.05 ) (0.11 ) (0.13 ) (0.05 ) (0.34 ) Distributions declared per common share 0.178 0.178 0.180 0.180 0.716

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated all subsequent event activity through the date these consolidated financial statements were available to be issued. Distributions Paid On January 2, 2018 , the Company paid distributions of $4,595,301 , which related to distributions declared for each day in the period from December 1, 2017 through December 31, 2017 . All such distributions were paid in cash. On February 1, 2018 , the Company paid distributions of $4,594,989 , which related to distributions declared for each day in the period from January 1, 2018 through January 31, 2018 . All such distributions were paid in cash. On March 1, 2018 , the Company paid distributions of $4,140,790 , which related to distributions declared for each day in the period from February 1, 2018 through February 28, 2018 . All such distributions were paid in cash. Redemption On January 30, 2018 , the Company redeemed 181,404 shares of its common stock for a total redemption value of $2,000,000 , or $11.03 per share, pursuant to the Company’s share repurchase program. Sale of The Moorings Apartments On January 5, 2018 , the Company, through SIR Moorings, LLC (“SIR Moorings”), an indirect, wholly-owned subsidiary of the Company, sold its fee simple interest in The Moorings Apartments, a 216 -unit residential property located in Roselle, Illinois, to an unaffiliated third-party buyer. SIR Moorings sold The Moorings Apartments for an aggregate sales price of $28,100,000 , excluding closing costs. Sale of Arrowhead Apartment Homes On January 31, 2018 , the Company, through SIR Arrowhead, LLC (“SIR Arrowhead”), an indirect, wholly-owned subsidiary of the Company, sold its fee simple interest in Arrowhead Apartment Homes, a 200 -unit residential property located in Palatine, Illinois, to an unaffiliated third-party buyer. SIR Arrowhead sold Arrowhead Apartment Homes for an aggregate sales price of $23,600,000 , excluding closing costs. Sale of Willow Crossing Apartments On February 28, 2018 , the Company, through SIR Willow Crossing, LLC (“SIR Willow Crossing”), an indirect, wholly-owned subsidiary of the Company, sold its fee simple interest in Willow Crossing Apartments, a 579 -unit residential property located in Elk Grove, Illinois, to an unaffiliated third-party buyer. SIR Willow Crossing sold Willow Crossing Apartments for an aggregate sales price of $79,000,000 , excluding closing costs. Estimated Value per Share On March 13, 2018 , the Company’s board of directors determined an estimated value per share of the Company’s common stock of $10.84 as of December 31, 2017 . Distribution Declared On March 20, 2018, the Company’s board of directors approved and authorized a daily distribution to stockholders of record as of the close of business on each day for the period commencing on April 1, 2018, and ending on June 30, 2018. The distributions will be equal to $0.001683 per share of the Company’s common stock per day, which if paid each day over a 365-day period is equivalent to a 6.0% annualized distribution rate based on a purchase price of $10.24 per share of common stock. The distributions for each record date in April 2018, May 2018 and June 2018 will be paid in May 2018, June 2018 and July 2018, respectively. The distributions will be payable to stockholders from legally available funds therefor. Tender Offer The Company’s board of directors approved the Company’s plan to pursue an issuer tender offer for up to $100 million in shares of the Company’s common stock at $9.00 per share. Suspension of Share Repurchase Program In connection with the board of directors’ decision to pursue a tender offer, on March 20, 2018, the Company’s board of directors elected to suspend the Company’s share repurchase program, effective upon 30 days’ notice to stockholders. No outstanding redemption requests as of April 28, 2018 or future redemption requests received after April 28, 2018 will be processed. The Company’s board of directors may in the future reinstate the share repurchase program, although there is no assurance as to if or when this will happen.

Scheule III. REAL ESTATE AND AC

Scheule III. REAL ESTATE AND ACCUMULATED DEPRECIATION AND AMORTIZATION	12 Months Ended
	Dec. 31, 2017
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Real Estate Assets and Accumulated Depreciation and Amortization	Description Location Owner-ship Percent Encumbrances (1) Initial Cost of Company Cost Capitalized Subsequent to Acquisition Gross Amount at which Carried at Close of Period Accumulated Depreciation and Amortization Original Date of Construction Date Acquired Land Building and Improvements (2) Total Land Building and Improvements (2) Total (3) Clarion Park Apartments Olathe, KS 100% $ 7,971,245 $ 1,470,991 $ 9,744,009 $ 11,215,000 $ 891,623 $ 1,470,991 $ 10,353,712 $ 11,824,704 $ (2,761,466 ) 1994 6/28/11 Truman Farm Villas Grandview, MO 100% 5,350,567 842,987 8,257,013 9,100,000 1,106,718 842,987 9,123,102 9,966,089 (2,502,288 ) 2008 12/22/11 EBT Lofts Kansas City, MO 100% 5,060,029 460,362 8,114,638 8,575,000 739,956 460,362 8,512,276 8,972,638 (2,141,890 ) 1899 12/30/11 Renaissance St. Andrews Louisville, KY 100% 8,357,513 838,685 11,661,315 12,500,000 1,160,711 838,685 12,579,622 13,418,307 (3,086,741 ) 2001 2/17/12 Spring Creek of Edmond Edmond, OK 100% 17,069,537 2,346,503 17,602,343 19,948,846 950,341 2,346,503 18,147,292 20,493,795 (4,438,904 ) 1974 3/9/12 Montclair Parc Apartments Oklahoma City, OK 100% 22,255,805 3,325,556 32,424,444 35,750,000 1,570,987 3,325,556 32,809,836 36,135,392 (7,443,135 ) 1999 4/26/12 Sonoma Grande Apartments Tulsa, OK 100% 20,920,589 2,737,794 29,462,206 32,200,000 890,318 2,737,794 29,802,911 32,540,705 (6,806,899 ) 2009 5/24/12 Estancia Apartments Tulsa, OK 100% 20,500,000 2,544,634 27,240,628 29,785,262 801,624 2,544,634 27,520,688 30,065,322 (6,134,374 ) 2006 6/29/12 Valley Farms Apartments Louisville, KY 100% 9,421,511 724,771 14,375,229 15,100,000 559,050 724,771 14,673,690 15,398,461 (3,078,593 ) 2007 8/30/12 Hilliard Park Apartments Hilliard, OH 100% 12,668,570 1,413,437 18,484,692 19,898,129 883,287 1,413,437 18,962,658 20,376,095 (4,024,722 ) 2000 9/11/12 Sycamore Terrace Apartments Terre Haute, IN 100% 17,821,492 1,321,194 21,852,963 23,174,157 373,442 1,321,194 21,780,821 23,102,015 (4,387,251 ) 2011/2013 9/20/12, 3/5/14 Hilliard Summit Apartments Hilliard, OH 100% 15,375,368 1,536,795 22,639,028 24,175,823 450,787 1,536,795 22,641,163 24,177,958 (4,640,794 ) 2012 9/28/12 Springmarc Apartments San Marcos, TX 100% 14,200,991 1,917,909 20,027,929 21,945,838 304,306 1,917,909 19,900,357 21,818,266 (4,070,502 ) 2008 10/19/12 Renaissance at St. Andrews Condominiums Louisville, KY 100% — 92,255 1,282,745 1,375,000 398,992 92,255 1,655,073 1,747,328 (396,701 ) 2001 10/31/12 Arrowhead Apartments Palatine, IL 100% 11,527,640 2,094,728 14,655,272 16,750,000 649,415 2,094,728 14,902,088 16,996,816 (3,025,710 ) 1976 11/30/12 The Moorings Apartments Roselle, IL 100% 13,934,462 2,250,208 17,999,792 20,250,000 1,800,800 2,250,208 19,379,126 21,629,334 (4,011,976 ) 1976 11/30/12 Forty-57 Apartments Lexington, KY 100% 36,312,924 3,055,614 49,444,386 52,500,000 1,170,324 3,055,614 49,852,825 52,908,439 (10,081,619 ) 2008 12/20/12 Keystone Farms Apartments Nashville, TN 100% 5,723,070 1,052,401 7,347,599 8,400,000 563,464 1,052,401 7,731,204 8,783,605 (1,633,180 ) 1998 12/28/12 Riverford Crossing Apartments Frankfort, KY 100% 20,647,194 2,595,387 27,404,613 30,000,000 754,674 2,595,387 27,617,253 30,212,640 (5,746,961 ) 2011 12/28/12 Valley Farms North Louisville, KY 100% 9,469,959 2,212,402 3,062,598 5,275,000 9,476,836 2,212,402 12,473,398 14,685,800 (1,420,780 ) 2010 12/28/12 Montecito Apartments Austin, TX 100% 13,116,770 3,081,522 15,918,478 19,000,000 2,500,159 3,081,522 17,984,441 21,065,963 (4,143,855 ) 1984 12/31/12 Description Location Owner-ship Percent Encumbrances (1) Initial Cost of Company Cost Capitalized Subsequent to Acquisition Gross Amount at which Carried at Close of Period Accumulated Depreciation and Amortization Original Date of Construction Date Acquired Land Building and Improvements (2) Total Land Building and Improvements (2) Total (3) Hilliard Grand Apartments Dublin, OH 100% $ 28,758,708 $ 2,657,734 $ 38,012,528 $ 40,670,262 $ 532,915 $ 2,657,734 $ 37,728,776 $ 40,386,510 $ (7,317,754 ) 2010 12/31/12 The Hills at Fair Oaks Fair Oaks Ranch, TX 100% 23,441,688 3,008,363 31,700,639 34,709,002 313,479 3,008,363 31,388,326 34,396,689 (6,104,552 ) 2012 1/31/13 Library Lofts East Kansas City, MO 100% 8,345,925 1,669,405 11,080,595 12,750,000 416,653 1,669,405 11,291,281 12,960,686 (2,257,472 ) 1906/1923 2/28/13 Deep Deuce at Bricktown Oklahoma City, OK 100% 24,260,315 2,529,318 37,266,648 39,795,966 5,865,351 2,580,318 42,405,923 44,986,241 (10,042,782 ) 2001 3/28/13 Retreat at Quail North Oklahoma City, OK 100% 16,480,903 1,700,810 24,025,543 25,726,353 409,298 1,700,810 23,946,198 25,647,008 (4,562,139 ) 2012 6/12/13 The Lodge at Trails Edge Indianapolis, IN 100% 11,798,975 2,389,613 16,128,107 18,517,720 706,515 2,389,613 16,449,002 18,838,615 (3,064,098 ) 1981 6/18/13 Arbors of Carrollton Carrollton, TX 100% 5,843,116 1,424,432 7,560,527 8,984,959 724,810 1,424,432 8,061,147 9,485,579 (1,677,861 ) 1984 7/3/13 Waterford on the Meadow Plano, TX 100% 15,520,062 2,625,024 20,849,131 23,474,155 3,041,815 2,625,024 23,325,780 25,950,804 (4,722,731 ) 1984 7/3/13 Tapestry Park Apartments Birmingham , AL 100% 43,655,146 3,277,884 47,118,797 50,396,681 284,310 3,277,884 46,764,643 50,042,527 (8,522,634 ) 2012/2014 8/13/13, 12/1/14 Dawntree Apartments Carrollton, TX 100% 14,800,655 3,135,425 21,753,469 24,888,894 2,076,142 3,135,425 23,227,150 26,362,575 (4,647,489 ) 1982 8/15/13 Stuart Hall Lofts Kansas City, MO 100% 16,008,257 1,585,035 15,264,965 16,850,000 168,175 1,585,035 15,148,381 16,733,416 (2,729,119 ) 1910 8/27/13 BriceGrove Park Apartments Canal Winchester, OH 100% 17,103,335 1,596,212 18,503,788 20,100,000 764,467 1,596,212 18,817,435 20,413,647 (3,505,866 ) 2002 8/29/13 Retreat at Hamburg Place Lexington, KY 100% 12,052,239 1,605,839 14,694,161 16,300,000 344,373 1,605,839 14,710,619 16,316,458 (2,727,552 ) 2013 9/5/13 The Heights Apartments Houston, TX 100% 38,272,259 9,869,925 27,130,075 37,000,000 2,913,086 9,869,925 28,681,430 38,551,355 (6,182,589 ) 1977 9/30/13 Villas at Huffmeister Houston, TX 100% 27,184,269 5,858,663 31,741,337 37,600,000 1,620,389 5,858,663 32,641,310 38,499,973 (6,120,866 ) 2007 10/10/13 Villas at Kingwood Kingwood, TX 100% 35,325,595 6,512,468 33,637,532 40,150,000 1,993,354 6,512,468 34,842,064 41,354,532 (6,600,161 ) 2008 10/10/13 Waterford Place at Riata Ranch Cypress, TX 100% 17,285,905 3,184,857 20,215,143 23,400,000 959,492 3,184,857 20,674,645 23,859,502 (3,948,393 ) 2008 10/10/13 Carrington Place Houston, TX 100% 27,323,636 5,450,417 27,449,583 32,900,000 1,683,415 5,450,417 28,438,837 33,889,254 (5,227,739 ) 2004 11/7/13 Carrington Champion Forest Houston, TX 100% 24,920,866 3,760,329 29,239,671 33,000,000 1,252,728 3,760,329 29,876,504 33,636,833 (5,470,712 ) 2008 11/7/13 Carrington Park at Huffmeister Houston, TX 100% 20,256,062 3,241,747 21,908,253 25,150,000 1,025,576 3,241,747 22,409,484 25,651,231 (4,209,680 ) 2008 11/7/13 Willow Crossing Elk Grove Village, IL 100% 57,665,058 8,091,870 49,908,130 58,000,000 8,010,749 8,091,870 56,203,972 64,295,842 (10,993,070 ) 1977-81 11/20/13 Echo at Katy Ranch Katy, TX 100% — 4,402,862 30,419,853 34,822,715 566,428 4,402,862 30,512,561 34,915,423 (5,114,124 ) 2013 12/19/13 Description Location Owner-ship Percent Encumbrances (1) Initial Cost of Company Cost Capitalized Subsequent to Acquisition Gross Amount at which Carried at Close of Period Accumulated Depreciation and Amortization Original Date of Construction Date Acquired Land Building and Improvements (2) Total Land Building and Improvements (2) Total (3) Heritage Grand at Sienna Plantation Missouri City, TX 100% $ 17,038,807 $ 3,776,547 $ 22,762,411 $ 26,538,958 $ 409,431 $ 3,776,547 $ 22,625,701 $ 26,402,248 $ (3,956,992 ) 2012 12/20/13 Mallard Crossing Loveland, OH 100% 33,534,900 2,383,256 37,416,744 39,800,000 1,460,565 2,383,256 38,206,736 40,589,992 (6,171,368 ) 1997 12/27/13 Reserve at Creekside Chattanooga, TN 100% 14,217,203 1,344,233 17,530,767 18,875,000 392,193 1,344,233 17,570,936 18,915,169 (2,811,132 ) 2004 3/28/14 Mapleshade Park Dallas, TX 100% 19,265,284 3,585,171 19,739,829 23,325,000 2,026,881 3,585,171 21,158,111 24,743,282 (3,672,956 ) 1995 3/31/14 Oak Crossing Fort Wayne, IN 100% 17,721,534 2,005,491 22,224,509 24,230,000 338,393 2,005,491 22,146,431 24,151,922 (3,241,482 ) 2012-13 6/3/14 $ 875,785,938 $ 130,589,065 $ 1,074,284,655 $ 1,204,873,720 $ 68,298,797 $ 130,640,065 $ 1,117,656,919 $ 1,248,296,985 $ (221,581,654 ) ________________ (1) Encumbrances include the unamortized portion of loan premiums on assumed debt allocated to individual assets in the aggregate amount of $0.7 million and net deferred financing costs of $5,109,819 as of December 31, 2017 . (2) Building and improvements include tenant origination and absorption costs and other intangible assets. (3) The aggregate cost of real estate for federal income tax purposes was $1.29 billion (unaudited) as of December 31, 2017 . A summary of activity for real estate and accumulated depreciation for the years ended December 31, 2017 , 2016 and 2015 : 2017 2016 2015 Real estate: Balance at the beginning of the year $ 1,694,278,958 $ 1,666,901,082 $ 1,636,953,413 Improvements 15,621,609 28,485,659 30,484,330 Cost of real estate sold (461,332,750 ) — — Write-off of disposed and fully depreciated and fully amortized assets (270,832 ) (1,107,783 ) (536,661 ) Balance at the end of the year $ 1,248,296,985 $ 1,694,278,958 $ 1,666,901,082 Accumulated depreciation and amortization: Balance at the beginning of the year $ 232,744,083 $ 163,445,987 $ 98,342,452 Depreciation and amortization expense 67,755,152 69,513,484 65,640,196 Write-off of accumulated depreciation and amortization of real estate assets sold (78,793,834 ) — — Write-off of disposed and fully depreciated and fully amortized assets (123,747 ) (215,388 ) (536,661 ) Balance at the end of the year $ 221,581,654 $ 232,744,083 $ 163,445,987

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation and Basis of Presentation The consolidated financial statements include the accounts of the Company, the consolidated variable interest entity (“VIE”) that the Company controls and of which the Company is the primary beneficiary, and the Operating Partnership’s subsidiaries. All significant intercompany balances and transactions are eliminated in consolidation. The financial statements of the Company’s subsidiaries are prepared using accounting policies consistent with those of the Company.
Basis of Presentation	The accompanying consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) as contained within the Financial Accounting Standards Board (“FASB”), Accounting Standards Codification (“ASC”) and the rules and regulations of the SEC.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires the Company to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could materially differ from those estimates.
Real Estate Assets	Real Estate Assets Depreciation and Amortization Real estate costs related to the development, construction and improvement of properties are capitalized. Acquisition costs related to business combinations are expensed as incurred. Acquisition costs related to asset acquisitions are capitalized. Repair and maintenance and tenant turnover costs are charged to expense as incurred and significant replacements and betterments are capitalized. Repair and maintenance and tenant turnover costs include all costs that do not extend the useful life of the real estate asset. The Company considers the period of future benefit of an asset to determine its appropriate useful life and anticipates the estimated useful lives of assets by class to be generally as follows: Buildings 27.5 years Building improvements 5-25 years Tenant improvements Shorter of lease term or expected useful life Tenant origination and absorption costs Remaining term of related lease Furniture, fixtures, and equipment 5-10 years Real Estate Purchase Price Allocation Prior to the Company’s adoption of ASU 2017-01 (as later defined) in January 2017, the Company recorded the acquisition of income-producing real estate or real estate that will be used for the production of income as a business combination. All assets acquired and liabilities assumed in a business combination were measured at their acquisition-date fair values. Acquisition costs were expensed as incurred. Upon adoption of ASU 2017-01, the Company records the acquisition of income-producing real estate or real estate that are used for the production of income as an asset acquisition. All assets acquired and liabilities assumed in the asset acquisition are measured at their acquisition date fair values. Acquisition costs are capitalized and allocated between land, buildings and improvements and tenant origination and associated costs on the consolidated balance sheet. The Company assesses the acquisition-date fair values of all tangible assets, identifiable intangible assets and assumed liabilities using methods similar to those used by independent appraisers (e.g., discounted cash flow analysis) and that utilize appropriate discount and/or capitalization rates and available market information. Estimates of future cash flows are based on a number of factors including historical operating results, known and anticipated trends, and market and economic conditions. The fair value of tangible assets of an acquired property considers the value of the property as if it was vacant. Intangible assets include the value of in-place leases, which represents the estimated value of the net cash flows of the in-place leases to be realized, as compared to the net cash flows that would have occurred had the property been vacant at the time of acquisition and subject to lease-up. The Company estimates the value of tenant origination and absorption costs by considering the estimated carrying costs during hypothetical expected lease-up periods, considering current market conditions. In estimating carrying costs, the Company estimates the amount of lost rentals using market rates during the expected lease-up periods. The Company amortizes the value of in-place leases to expense over the remaining non-cancelable term of the respective leases. Should a tenant terminate its lease, the unamortized portion of the in-place lease value and customer relationship intangibles would be charged to expense in that period. The Company records above-market and below-market in-place lease values for acquired properties based on the present value (using an interest rate that reflects the risks associated with the leases acquired) of the difference between (1) the contractual amounts to be paid pursuant to the in-place leases and (2) the Company’s estimate of fair market lease rates for the corresponding in-place leases, measured over a period equal to the remaining non-cancelable term of the lease. The Company amortizes any capitalized above-market or below-market lease values as a reduction or increase to rental income over the remaining non-cancelable terms of the respective leases. The total amount of other lease-related intangible assets acquired will be further allocated to in-place lease values and customer relationship intangible values based on the Company’s evaluation of the specific characteristics of each tenant’s lease and its overall relationship with that respective tenant. Characteristics that the Company considers in allocating these values include the nature and extent of existing business relationships with the tenant, growth prospects for developing new business with the tenant, and the tenant’s credit quality and expectations of lease renewals (including those existing under the terms of the lease agreement), among other factors. The total amount of non-lease-related intangible assets, including amenity access agreements, tax abatement agreements or other contract rights assumed as part of the acquisition of certain properties, will be allocated to other intangible assets based on the present value of the difference between contractual amounts to be paid pursuant to the contracts assumed and the Company’s estimate of the fair market contract rates for corresponding contracts measured over a period equal to the remaining non-cancelable term of the contracts assumed. Other intangible assets are amortized using the straight-line method over the remaining non-cancelable term of the related contracts. Estimates of the fair values of the tangible assets, identifiable intangible assets and assumed liabilities require the Company to make significant assumptions to estimate market lease rates, property-operating expenses, carrying costs during lease-up periods, discount rates, market absorption periods, and the number of years the property will be held for investment. The use of inappropriate assumptions could result in an incorrect valuation of acquired tangible assets, identifiable intangible assets and assumed liabilities, which could impact the amount of the Company’s net income (loss). Sale of Real Estate Assets Property sales or dispositions are recorded when title transfers to unrelated third parties, contingencies have been removed and sufficient cash consideration has been received by the Company. Upon disposition, the related costs and accumulated depreciation are removed from the respective accounts. Any gain or loss on sale is recognized in accordance with GAAP. The Company recognizes gains on sales of real estate either in total or deferred for a period of time, depending on whether a sale has been consummated, the extent of the buyer’s investment in the property being sold, whether the receivable is subject to future subordination, and the degree of the Company’s continuing involvement with the property after the sale. If the criteria for profit recognition under the full-accrual method are not met, the Company will defer gain recognition and account for the continued operations of the property by applying the percentage-of-completion, reduced profit, deposit, installment or cost recovery method, as appropriate, until the appropriate criteria are met. The Company classifies real estate assets as real estate held for sale once the criteria, as defined by GAAP, have been met. Impairment of Real Estate Assets The Company accounts for its real estate assets in accordance with ASC 360— Property, Plant and Equipment (“ASC 360”). ASC 360 requires the Company to continually monitor events and changes in circumstances that could indicate that the carrying amounts of the Company’s real estate and related intangible assets may not be recoverable. When indicators of potential impairment suggest that the carrying value of real estate and related intangible assets and liabilities may not be recoverable, the Company assesses the recoverability of the assets by estimating whether the Company will recover the carrying value of the asset through its undiscounted future cash flows and its eventual disposition. Based on this analysis, if the Company does not believe that it will be able to recover the carrying value of the real estate and related intangible assets and liabilities, the Company records an impairment loss to the extent that the carrying value exceeds the estimated fair value of the real estate and related intangible assets and liabilities. If any assumptions, projections or estimates regarding an asset changes in the future, the Company may have to record an impairment to reduce the net book value of such individual asset.
Rents and Other Receivables	Rents and Other Receivables The Company will periodically evaluate the collectability of amounts due from tenants and maintain an allowance for doubtful accounts for estimated losses resulting from the inability of tenants to make required payments under lease agreements. The Company exercises judgment in establishing these allowances and considers payment history and current credit status of tenants in developing these estimates. Due to the short-term nature of the operating leases, the Company does not maintain a deferred rent receivable related to the straight-lining of rents.
Revenue Recognition	Revenue Recognition The Company leases apartment and condominium units under operating leases with terms generally of one year or less. Generally, credit investigations are performed for prospective residents and security deposits are obtained. The Company will recognize minimum rent, including rental abatements, concessions and contractual fixed increases attributable to operating leases, on a straight-line basis over the term of the related lease and amounts expected to be received in later years will be recorded as deferred rents. The Company records property operating expense reimbursements due from tenants for common area maintenance, real estate taxes, and other recoverable costs in the period the related expenses are incurred.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. Cash equivalents may include cash and short-term investments. Short-term investments are stated at cost, which approximates fair value. As of December 31, 2017 and 2016 , the Company had amounts in excess of federally insured limits in deposit accounts with a financial institution. The Company limits such deposits to financial institutions with high credit standing. Restricted Cash Restricted cash represents those cash accounts for which the use of funds is restricted by loan covenants and cash placed with a qualified intermediary for reinvestment under Section 1031 of the Internal Revenue Code (“1031 Exchange”). As of December 31, 2017 and 2016 , the Company had a restricted cash balance of $31,442,700 and $15,466,891 , respectively, which represents amounts set aside as impounds for future property tax payments, property insurance payments and tenant improvement payments as required by agreements with the Company’s lenders, in addition to $17,197,810 and $0 of cash proceeds from property sales that are being held by qualified intermediaries for purposes of facilitating a 1031 Exchange as of December 31, 2017 and 2016 , respectively.
Short-term Investments	Short-term Investments Short-term investments consist of any highly-liquid securities that have an original maturity of less than one year but greater than three months at the time of purchase. As of December 31, 2016 , short-term investments consisted of $30,000,000 held in a certificate of deposit and is included in short-term investments on the accompanying consolidated balance sheets. The certificate of deposit originally matured on March 28, 2017; however, upon maturity, the balance was rolled into a new six-month certificate of deposit. The new certificate of deposit matured on September 26, 2017, and was not renewed. As of December 31, 2017 , there were no short-term investments. The short-term investment was classified as held-to-maturity and was recorded at the amortized cost on the accompanying consolidated balance sheets. During the years ended December 31, 2017 and December 31, 2016 , $278,883 and $84,750 was included in tenant reimbursements and other on the accompanying consolidated statements of operations.
Deferred Financing Costs	Deferred Financing Costs The Company capitalizes deferred financing costs such as commitment fees, legal fees and other third party costs associated with obtaining commitments for financing that result in a closing of such financing, as a contra liability against the respective outstanding debt balances. The Company amortizes these costs over the terms of the respective financing agreements using the effective interest method. The Company expenses unamortized deferred financing costs when the associated debt is refinanced or repaid before maturity unless specific rules are met that would allow for the carryover of such costs to the refinanced debt. Costs incurred in seeking financing transactions that do not close are expensed in the period in which it is determined that the financing will not close.
Derivative Financial Instruments	Derivative Financial Instruments The Company accounts for its derivative financial instruments in accordance with ASC 815— Derivatives and Hedging . The Company’s objective in using derivatives is to add stability to interest expense and to manage the Company’s exposure to interest rate movements or other identified risks. To accomplish these objectives, the Company may use various types of derivative instruments to manage fluctuations in cash flows resulting from interest rate risk attributable to changes in the benchmark interest rate of LIBOR or other applicable benchmark rates. The Company measures its derivative instruments and hedging activities at fair value and records them as an asset or liability, depending on its rights or obligations under the applicable derivative contract. For derivatives designated as fair value hedges, the changes in the fair value of both the derivative instrument and the hedged items are recorded in earnings. Derivatives used to hedge the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For derivatives designated as cash flow hedges, the effective portions of changes in fair value of the derivatives are reported in other comprehensive income (loss) and are subsequently reclassified into earnings when the hedged item affects earnings. Changes in fair value of derivative instruments not designated as hedges and ineffective portions of hedges are recognized in earnings in the affected period. The Company assesses the effectiveness of each hedging relationship by comparing the changes in fair value or cash flows of the derivative hedging instrument with the changes in fair value or cash flows of the designated hedged item or transaction.
Fair Value Measurements	Fair Value Measurements Under GAAP, the Company is required to measure certain financial instruments at fair value on a recurring basis. In addition, the Company is required to measure other assets and liabilities at fair value on a non-recurring basis (e.g., carrying value of impaired real estate loans receivable and long-lived assets). Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The GAAP fair value framework uses a three-tiered approach. Fair value measurements are classified and disclosed in one of the following three categories: • Level 1: unadjusted quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities; • Level 2: quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-derived valuations in which significant inputs and significant value drivers are observable in active markets; and • Level 3: prices or valuation techniques where little or no market data is available that requires inputs that are both significant to the fair value measurement and unobservable. When available, the Company utilizes quoted market prices from an independent third-party source to determine fair value and will classify such items in Level 1 or Level 2. In instances where the market is not active, regardless of the availability of a nonbinding quoted market price, observable inputs might not be relevant and could require the Company to make a significant adjustment to derive a fair value measurement. Additionally, in an inactive market, a market price quoted from an independent third party may rely more on models with inputs based on information available only to that independent third party. When the Company determines the market for a financial instrument owned by the Company to be illiquid or when market transactions for similar instruments do not appear orderly, the Company uses several valuation sources (including internal valuations, discounted cash flow analysis and quoted market prices) and will establish a fair value by assigning weights to the various valuation sources. The following describes the valuation methodologies used by the Company to measure fair value, including an indication of the level in the fair value hierarchy in which each asset or liability is generally classified. Interest rate cap agreements - The Company has entered into certain interest rate cap agreements. These derivatives did not qualify as fair value hedges. Fair value was based on a model-driven valuation using the associated variable rate curve and an implied market volatility, both of which were observable at commonly quoted intervals for the full term of the interest rate cap agreements. Therefore, the Company’s interest rate cap agreements were classified within Level 2 of the fair value hierarchy and are included in other assets in the accompanying consolidated balance sheets.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The accompanying consolidated balance sheets include the following financial instruments: cash and cash equivalents, restricted cash, short-term investments, rents and other receivables, accounts payable and accrued liabilities, distributions payable, due to affiliates and notes payable. The Company considers the carrying value of cash and cash equivalents, restricted cash, rents and other receivables, accounts payable and accrued liabilities and distributions payable to approximate the fair value of these financial instruments based on the short duration between origination of the instruments and their expected realization. The Company considers the carrying value of short-term investments to approximate fair value as it was recorded at amortized cost. The fair value of amounts due to affiliates is not determinable due to the related party nature of such amounts. The fair value of the notes payable is estimated using a discounted cash flow analysis using borrowing rates available to the Company for debt instruments with similar terms and maturities.
Accounting for Stock-Based Compensation	Accounting for Stock-Based Compensation The Company amortizes the fair value of stock-based compensation awards to expense over the vesting period and records any dividend equivalents earned as dividends for financial reporting purposes. Stock-based compensation awards to independent directors are valued at the fair value on the date of grant and amortized as an expense over the vesting period. Awards to non-employees are remeasured at fair value each reporting period and amortized as an expense over the vesting period.
Distribution Policy	Distribution Policy The Company has elected to be taxed, and currently qualifies as, a REIT beginning with its taxable year ending December 31, 2010. To maintain its qualification as a REIT, the Company intends to make distributions each taxable year equal to at least 90% of its REIT taxable income (which is determined without regard to the dividends paid deduction or net capital gain and which does not necessarily equal net income as calculated in accordance with GAAP). Distributions to stockholders are determined by the board of directors of the Company and are dependent upon a number of factors relating to the Company, including funds available for the payment of distributions, financial condition, the timing of property acquisitions, capital expenditure requirements and annual distribution requirements in order for the Company to qualify as a REIT under the Internal Revenue Code.
Operating Expenses	Operating Expenses Pursuant to the Advisory Agreement, the Company is limited in the amount of certain operating expenses it may record on a rolling four-quarter basis to the greater of 2% of average invested assets and 25% of net income. Operating expenses include all costs and expenses incurred by the Company, as determined under GAAP, that in any way are related to the operation of the Company, excluding expenses of raising capital, interest payments, taxes, property operating expenses, non-cash expenditures, incentive fees, acquisition fees and expenses and investment management fees.
Income Taxes	Income Taxes The Company elected to be taxed as a REIT under the Internal Revenue Code beginning with the tax year ended December 31, 2010. To continue to qualify as a REIT, the Company must meet certain organizational and operational requirements, including the requirement to distribute at least 90% of the Company’s annual REIT taxable income to stockholders (which is computed without regard to the dividends paid deduction or net capital gain and which does not necessarily equal net income as calculated in accordance with GAAP). As a REIT, the Company generally will not be subject to federal income tax to the extent it distributes qualifying dividends to its stockholders. If the Company fails to qualify as a REIT in any taxable year, it will be subject to federal income tax on its taxable income at regular corporate income tax rates and generally will not be permitted to qualify for treatment as a REIT for federal income tax purposes for the four taxable years following the year during which qualification is lost, unless the Internal Revenue Service grants the Company relief under certain statutory provisions. Such an event could materially adversely affect the Company’s net income and net cash available for distribution to stockholders. However, the Company believes it is organized and operates in such a manner as to qualify for treatment as a REIT. The Company follows the Income Taxes Topic of the ASC to recognize, measure, present and disclose in its accompanying consolidated financial statements uncertain tax positions that the Company has taken or expects to take on a tax return.
Per Share Data	Per Share Data Basic earnings (loss) per share attributable to common stockholders for all periods presented are computed by dividing net income (loss) by the weighted average number of shares of the Company’s common stock outstanding during the period. Diluted earnings (loss) per share is computed based on the weighted average number of shares of the Company’s common stock and all potentially dilutive securities, if any. Distributions declared per common share assume each share was issued and outstanding each day during the period. Nonvested shares of the Company’s restricted common stock give rise to potentially dilutive shares of the Company’s common stock. In accordance with FASB ASC Topic 260-10-45, Earnings Per Share , the Company uses the two-class method to calculate earnings (loss) per share. Basic earnings (loss) per share is calculated based on dividends declared and the rights of common shares and participating securities in any undistributed earnings, which represents net income (loss) remaining after deduction of dividends declared during the period. The undistributed earnings (loss) are allocated to all outstanding common shares based on the relative percentage of each class of shares.
Segment Disclosure	Segment Disclosure The Company has determined that it has one reportable segment with activities related to investing in multifamily properties. The Company’s investments in real estate are in different geographic regions, and management evaluates operating performance on an individual asset level. However, as each of the Company’s assets has similar economic characteristics, tenants and products and services, its assets have been aggregated into one reportable segment.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers ( Topic 606 ) (“ASU 2014-09”). The new guidance requires an entity to recognize the 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 and services. The new guidance supersedes the revenue requirements in Revenue Recognition ( Topic 605 ) and most industry-specific guidance throughout the Industry Topics of the Codification. The new guidance does not apply to lease contracts within the scope of Leases ( Topic 840 ). In August 2015, the FASB issued ASU 2015-14, Revenue from Contracts with Customers (Topic 606) , which delayed the effective date of the new guidance by one year, which resulted in the new guidance being effective for fiscal years, and interim periods within those years, beginning after December 15, 2017, and is to be applied retrospectively. Early adoption is permitted, but can be no earlier than the original public entity effective date of fiscal years, and interim periods within those years, beginning after December 15, 2016. The Company has selected the modified retrospective transition method with a cumulative effect recognized as of the date of adoption and will adopt the new standard effective January 1, 2018. Based on its assessment, the Company identified limited sources of revenues from non-lease components. Based on its assessment, the Company does not expect a material impact on its revenue recognition in the consolidated financial statements because these sources of revenue are immaterial to the consolidated financial statements. The Company also does not expect a material impact from adopting this new guidance in connection with its rental revenue, as rental revenue from leasing arrangements is specifically excluded from the standard. In February 2016, the FASB issued ASU 2016-02, Leases , (“ASU 2016-02”) amending the existing accounting standards for lease accounting, including requiring lessees to recognize most leases on their balance sheets and making targeted changes to lessor accounting. The new standard requires a modified retrospective transition approach. The guidance will be effective in the first quarter of 2019 and allows for early adoption. The Company is evaluating the impact of ASU 2016-02 on its leases both as it relates to the Company acting as a lessor and as a lessee. Based on the preliminary results of its evaluation, as it relates to the former, the Company does not expect any material impact on the recognition of leases in the consolidated financial statements because under this guidance, lessors will continue to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases, and operating leases. As it relates to the latter, the Company does not expect a material impact on the recognition of leases in the consolidated financial statements because the quantity of leased equipment by the Company is limited. The Company is finalizing its evaluation of ASU 2016-02 and plans to adopt ASU 2016-02 on January 1, 2019. In March 2016, the FASB issued ASU 2016-09, Compensation - Stock Compensation (Topic 718), Improvements to Employee Share-Based Payment Accounting , that simplifies several aspects of the accounting for employee share-based payment transactions for both public and nonpublic entities, including the accounting for income taxes, forfeitures and statutory tax withholding requirements, as well as classification in the statement of cash flows. The guidance is effective for annual reporting periods beginning after December 15, 2016, and interim periods within those years. The Company did not experience a material impact from adopting this new guidance as of January 1, 2017. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments (a consensus of the Emerging Issues Task Force) (“ASU 2016-15”), that clarifies how certain cash receipts and cash payments should be classified on the statement of cash flows. ASU 2016-15 addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The guidance is effective for annual reporting periods beginning after December 15, 2017, and interim periods within those years. Early adoption is permitted. Upon adoption in 2016, the Company reclassified payments for debt extinguishment costs of $0 , $3,202,337 and $0 from cash flows from operating activities to cash flows from financing activities as of December 31, 2017 , 2016 and 2015 , respectively. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (“ASU No. 2016-18”). ASU No. 2016-18 requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, restricted cash and restricted cash equivalents. Therefore, amounts generally described as restricted cash 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. ASU No. 2016-18 is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The Company will adopt this guidance January 1, 2018 and will begin presenting restricted cash along with cash and cash equivalents in its consolidated statements of cash flows. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the definition of business , that clarifies 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 businesses. This ASU provides a screen to determine when a set is not a business. If the screen is not met, it (1) requires that to be considered a business, a set must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) removes the evaluation of whether a market participant could replace the missing elements. The guidance is effective for annual reporting periods beginning after December 15, 2017, and interim periods within those years. Early adoption is permitted. Upon adoption of this new guidance during the year ended December 31, 2017 , the Company did not experience a material impact. In February 2017, the FASB issued ASU 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (“Subtopic 610-20”): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (“ASU 2017-05”), that clarifies that a financial asset is within the scope of Subtopic 610-20 if it meets the definition of an in substance nonfinancial asset and defines the term in substance nonfinancial asset. ASU 2017-05 also clarifies that nonfinancial assets within the scope of Subtopic 610-20 may include nonfinancial assets transferred within a legal entity to a counterparty. Subtopic 610-20, which was issued in May 2014 as part of ASU 2014-09 (discussed above), provides guidance for recognizing gains and losses from the transfer of nonfinancial assets in contracts with noncustomers. An entity is required to apply amendments in ASU 2017-05 at the same time it applies the amendments in ASU 2014-09 (discussed above). ASU 2017-05 requires retrospective application and is effective for fiscal years beginning after December 15, 2017, including interim reporting periods within those fiscal years. Early adoption is permitted. The Company will adopt this new guidance on January 1, 2018, and expects there to be an impact on the gain recognized related to the sale of the Second Closing Properties (as defined in Note 3). The sale of the Second Closing Properties is considered a partial sale and the Company no longer controls the Second Closing Properties after the sale. The retained noncontrolling interest is required to be recognized at fair value and a full gain on sale is required to be recognized under the new guidance. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”). The FASB issued ASU 2017-09 to provide clarity and reduce both (1) diversity in practice and (2) cost and complexity when applying the guidance in Topic 718, Compensation - Stock Compensation , to a change to the terms or conditions of a share-based payment award. The amendments in ASU 2017-09 provide guidance about which changes to the terms or conditions of a share-based payment award require an entity to apply modification accounting in Topic 718. ASU No. 2017-09 requires prospective application and is effective for annual periods beginning after December 15, 2017, including interim periods within those fiscal years. Early adoption is permitted. The Company will adopt this guidance January 1, 2018 and does not expect a material impact on its consolidated financial statements and related disclosures from its adoption.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Useful Lives of Assets by Class	The Company considers the period of future benefit of an asset to determine its appropriate useful life and anticipates the estimated useful lives of assets by class to be generally as follows: Buildings 27.5 years Building improvements 5-25 years Tenant improvements Shorter of lease term or expected useful life Tenant origination and absorption costs Remaining term of related lease Furniture, fixtures, and equipment 5-10 years
Summary of Assets Required to be Measured at Fair Value on a Recurring Basis	The following table reflects the Company’s assets required to be measured at fair value on a recurring basis on the consolidated balance sheets: December 31, 2017 Fair Value Measurements Using Level 1 Level 2 Level 3 Assets: Interest rate cap agreements $ — $ 51,646 $ — December 31, 2016 Fair Value Measurements Using Level 1 Level 2 Level 3 Assets: Interest rate cap agreements $ — $ 618,841 $ —

Real Estate (Tables)

Real Estate (Tables)	12 Months Ended
	Dec. 31, 2017
Real Estate [Abstract]
Schedule of Accumulated Depreciation and Amortization Related to the Consolidated Real Estate Properties and Related Intangibles	As of December 31, 2017 and 2016 , accumulated depreciation and amortization related to the Company’s consolidated real estate properties and related intangibles were as follows: December 31, 2017 Assets Land Building and Improvements Other Intangible Assets Total Real Estate Held for Investment Real Estate Held for Sale Investments in real estate $ 115,023,911 $ 972,272,325 $ 2,644,263 $ 1,089,940,499 $ 158,356,486 Less: Accumulated depreciation and amortization — (192,375,859 ) (699,199 ) (193,075,058 ) (28,506,597 ) Net investments in real estate and related lease intangibles $ 115,023,911 $ 779,896,466 $ 1,945,064 $ 896,865,441 $ 129,849,889 December 31, 2016 Assets Land Building and Improvements Other Intangible Assets Total Real Estate Held for Investment Real Estate Held for Sale Investments in real estate $ 114,972,911 $ 962,926,584 $ 2,644,263 $ 1,080,543,758 $ 613,735,200 Less: Accumulated depreciation and amortization — (146,961,045 ) (546,031 ) (147,507,076 ) (85,237,007 ) Net investments in real estate and related lease intangibles $ 114,972,911 $ 815,965,539 $ 2,098,232 $ 933,036,682 $ 528,498,193
Schedule of Future Amortization of Acquired Other Intangible Assets	The future amortization of the Company’s acquired other intangible assets as of December 31, 2017 and thereafter is as follows: 2018 $ 153,168 2019 153,168 2020 153,168 2021 153,168 2022 153,168 Thereafter 1,179,224 $ 1,945,064
Schedule of Future Minimum Rental Receipts from Properties under Non-cancelable Operating Leases Attributable to Commercial Office Tenants	The future minimum rental receipts from the Company’s properties under non-cancelable operating leases attributable to commercial office tenants as of December 31, 2017 and thereafter is as follows: 2018 $ 259,143 2019 180,858 2020 74,313 2021 76,535 2022 76,535 Thereafter 185,501 $ 852,885
Disposal Groups, Including Discontinued Operations	The results of operations for the years ended December 31, 2017 , 2016 and 2015 , for the disposed properties, including the properties contributed to the Joint Venture, were included in continuing operations on the Company’s consolidated statements of operations and are as follows: For the Year Ended December 31, 2017 2016 2015 Revenues: Rental income $ 46,450,562 $ 51,585,026 $ 49,329,436 Tenant reimbursements and other 6,383,148 7,090,653 6,330,963 Total revenues 52,833,710 58,675,679 55,660,399 Expenses: Operating, maintenance and management 15,863,468 16,579,083 15,338,184 Real estate taxes and insurance 10,162,131 10,634,970 11,065,115 Fees to affiliates 2,087,374 2,260,569 2,171,583 Depreciation and amortization 16,659,338 19,022,464 17,830,725 Interest expense 10,406,061 9,372,856 8,230,556 Loss on debt extinguishment 2,387,552 1,495,312 — General and administrative expenses 561,437 1,175,433 337,469 Total expenses $ 58,127,361 $ 60,540,687 $ 54,973,632 The results of operations from The Moorings Apartments , Arrowhead Apartment Homes and the Second Closing Properties for the years ended December 31, 2017 , 2016 and 2015 , which are summarized in the following table, were included in continuing operations on the Company’s consolidated statements of operations. For the Years Ended December 31, 2017 2016 2015 Revenues $ 21,889,939 $ 21,257,326 $ 19,748,536 Expenses 19,926,810 20,705,376 19,322,136 Total Income $ 1,963,129 $ 551,950 $ 426,400
Summarized Financial Information of Joint Venture	The table below sets out the properties contributed to the Joint Venture in the Transaction: Property Units Metro First Closing Properties: Ashley Oaks 462 San Antonio Audubon Park 256 Nashville Belmont 260 Dallas Cantare at Indian Lake Village 206 Nashville Cooper Creek 123 Louisville Grayson Ridge 240 Dallas Landing at Mansfield 336 Dallas Meritage at Steiner Ranch 502 Austin Montelena 232 Austin Richland Falls 276 Nashville Rosemont at Olmos Park 144 San Antonio Trails at Buda Ranch 264 Austin 3,301 Second Closing Properties: Arbors of Carrollton 131 Dallas Hills at Fair Oaks 288 San Antonio Keystone Farms 90 Nashville Renaissance St. Andrews 216 Louisville Renaissance St. Andrews Condominiums 30 Louisville Springmarc Apartments 240 Austin Valley Farms (1) 160 Louisville Valley Farms North 128 Louisville 1,283 4,584 _______________ (1) Includes SIR Valley Farms Clubhouse, LLC. Summarized financial information for the Joint Venture is: December 31, 2017 Assets: Real estate assets, net $ 374,277,205 Other assets 15,328,440 Total assets $ 389,605,645 Liabilities and equity: Notes payable, net $ 264,558,057 Other liabilities 11,525,292 Company’s capital 11,352,230 Other partner’s capital 102,170,066 Total liabilities and equity $ 389,605,645 For the Period from November 15, 2017 to December 31, 2017 Revenues $ 5,756,455 Expenses 11,330,228 Net loss $ (5,573,773 ) Company’s proportional net loss $ (557,377 ) Amortization of outside basis (106,519 ) Equity in loss of unconsolidated joint venture $ (663,896 )

Investment in Unconsolidated 26

Investment in Unconsolidated Joint Venture (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Summarized Financial Information of Joint Venture	The table below sets out the properties contributed to the Joint Venture in the Transaction: Property Units Metro First Closing Properties: Ashley Oaks 462 San Antonio Audubon Park 256 Nashville Belmont 260 Dallas Cantare at Indian Lake Village 206 Nashville Cooper Creek 123 Louisville Grayson Ridge 240 Dallas Landing at Mansfield 336 Dallas Meritage at Steiner Ranch 502 Austin Montelena 232 Austin Richland Falls 276 Nashville Rosemont at Olmos Park 144 San Antonio Trails at Buda Ranch 264 Austin 3,301 Second Closing Properties: Arbors of Carrollton 131 Dallas Hills at Fair Oaks 288 San Antonio Keystone Farms 90 Nashville Renaissance St. Andrews 216 Louisville Renaissance St. Andrews Condominiums 30 Louisville Springmarc Apartments 240 Austin Valley Farms (1) 160 Louisville Valley Farms North 128 Louisville 1,283 4,584 _______________ (1) Includes SIR Valley Farms Clubhouse, LLC. Summarized financial information for the Joint Venture is: December 31, 2017 Assets: Real estate assets, net $ 374,277,205 Other assets 15,328,440 Total assets $ 389,605,645 Liabilities and equity: Notes payable, net $ 264,558,057 Other liabilities 11,525,292 Company’s capital 11,352,230 Other partner’s capital 102,170,066 Total liabilities and equity $ 389,605,645 For the Period from November 15, 2017 to December 31, 2017 Revenues $ 5,756,455 Expenses 11,330,228 Net loss $ (5,573,773 ) Company’s proportional net loss $ (557,377 ) Amortization of outside basis (106,519 ) Equity in loss of unconsolidated joint venture $ (663,896 )

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets	As of December 31, 2017 and 2016 , other assets consisted of: December 31, 2017 2016 Prepaid expenses $ 2,132,212 $ 3,041,353 Interest rate cap agreements (Note 12) 51,646 618,841 Deposits 1,074,726 1,126,568 Other assets $ 3,258,584 $ 4,786,762

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Notes Payable Secured by Real Property	The following is a summary of mortgage notes payable, net secured by real property as of December 31, 2017 and 2016 : December 31, 2017 Interest Rate Range Weighted Average Interest Rate Type Number of Instruments Maturity Date Range Minimum Maximum Principal Outstanding Mortgage notes payable - fixed 32 4/1/2018 - 10/1/2056 3.19 % 5.75 % 3.89 % $ 416,673,854 Mortgage notes payable - variable (1) 14 10/1/2018 - 1/1/2026 1-Mo LIBOR + 2.02% 1-Mo LIBOR + 2.50% 3.86 % 372,481,000 Total mortgage notes payable, gross 46 3.87 % 789,154,854 Premium, net (2) 673,653 Deferred financing costs, net (3) (4,264,667 ) Total mortgage notes payable, net $ 785,563,840 December 31, 2016 Interest Rate Range Weighted Average Interest Rate Type Number of Instruments Maturity Date Range Minimum Maximum Principal Outstanding Mortgage notes payable - fixed 37 10/1/2017 - 10/1/2056 3.19 % 5.94 % 4.06 % $ 471,344,145 Mortgage notes payable - variable (1) 21 8/31/2017 - 1/1/2026 1-Mo LIBOR + 1.65% 1-Mo LIBOR + 2.65% 3.05 % 517,885,675 Total mortgage notes payable, gross 58 3.52 % 989,229,820 Premium/discount, net (2) 2,208,619 Deferred financing costs, net (3) (6,358,285 ) Total mortgage notes payable, net $ 985,080,154 _______________ (1) See Note 12 for a discussion of the interest rate cap agreements used to manage the exposure to interest rate movement on the Company’s variable rate loans. (2) The following table summarizes the debt premiums as of December 31, 2017 , including the unamortized portion included in the principal balance as well as amounts amortized as an offset to interest expense in the accompanying consolidated statements of operations: Unamortized Portion of Net Debt Premium as of December 31, 2017 Amortization of Net Debt Premium During the Years Ended December 31, 2017 2016 2015 $ 673,653 $ 1,129,960 $ 1,243,385 $ 1,234,793 (3) The following table summarizes the deferred financing costs, net related to mortgage notes payable as of December 31, 2017 and 2016 : December 31, 2017 2016 Deferred financing costs $ 8,215,716 $ 10,104,244 Less: accumulated amortization (3,951,049 ) (3,745,959 ) Deferred financing costs, net $ 4,264,667 $ 6,358,285
Summary of Debt Premiums and Discounts	The following table summarizes the debt premiums as of December 31, 2017 , including the unamortized portion included in the principal balance as well as amounts amortized as an offset to interest expense in the accompanying consolidated statements of operations: Unamortized Portion of Net Debt Premium as of December 31, 2017 Amortization of Net Debt Premium During the Years Ended December 31, 2017 2016 2015 $ 673,653 $ 1,129,960 $ 1,243,385 $ 1,234,793
Summary of Deferred Finance Costs	The following table summarizes the deferred financing costs, net related to mortgage notes payable as of December 31, 2017 and 2016 : December 31, 2017 2016 Deferred financing costs $ 8,215,716 $ 10,104,244 Less: accumulated amortization (3,951,049 ) (3,745,959 ) Deferred financing costs, net $ 4,264,667 $ 6,358,285
Schedule of Line of Credit Facilities	As of December 31, 2017 and 2016 , the advances obtained under the credit facility on July 29, 2016 are summarized in the following table: Amount of Advance as of December 31, Collateralized Property (1) 2017 2016 Ashley Oaks Apartment Homes (2) $ — $ 24,867,500 Trails at Buda Ranch (2) — 21,025,000 Deer Valley Apartments (2) — 22,982,500 Carrington Park at Huffmeister 20,430,500 20,430,500 Carrington Place 27,535,500 27,535,500 Carrington at Champion Forest 25,121,250 25,121,250 Audubon Park Apartments (2) — 16,602,500 Oak Crossing 17,980,000 17,980,000 Meritage at Steiner Ranch (2) — 58,580,000 91,067,250 235,124,750 Deferred financing costs, net on credit facility (3) (845,152 ) (2,488,624 ) Credit facility, net $ 90,222,098 $ 232,636,126 ___________ (1) Each property is pledged as collateral for repayment of all amounts advanced under the credit facility. (2) The outstanding amount was repaid in full in conjunction with such property’s disposition during the year ended December 31, 2017 . (3) Accumulated amortization related to deferred financing costs for the credit facility as of December 31, 2017 and December 31, 2016 , was $390,241 and $433,522 , respectively.
Summary of Aggregate Maturities	The following is a summary of the Company’s aggregate maturities as of December 31, 2017 : Maturities During the Years Ending December 31, Contractual Obligation Total 2018 2019 2020 2021 2022 Thereafter Principal payments on outstanding debt obligations (1) $ 880,222,104 $ 61,059,734 $ 100,037,883 $ 71,298,949 $ 123,518,437 $ 34,615,399 $ 489,691,702 ________________ (1) Projected principal payments on outstanding debt obligations are based on the terms of the notes payable agreements. Amounts exclude the amortization of the deferred financing costs and debt premiums associated with certain notes payable.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Restricted Stock Issued to Independent Directors as Compensation	for the years ended December 31, 2017 , 2016 and 2015 , for the restricted stock issued to the Company’s independent directors as compensation for services in connection with their initial election or re-election to the board of directors at the Company’s annual meeting, upon their departure from the board of directors, or in appreciation of their service and commitment to the Company is as follows: 2017 2016 2015 Nonvested shares at the beginning of the year 11,875 11,250 16,875 Granted shares 7,500 7,500 14,000 Vested shares (7,500 ) (6,875 ) (19,625 ) Nonvested shares at the end of the year 11,875 11,875 11,250 The weighted average fair value of restricted stock issued to the Company’s independent directors for the years ended December 31, 2017 , 2016 and 2015 is as follows: Grant Year Weighted Average Fair Value 2015 $ 10.35 2016 11.44 2017 11.65
Schedule of Repurchase Prices Under Share Repurchase Plan	The purchase price for shares repurchased under the Company’s share repurchase program is as follows: Share Purchase Anniversary Repurchase Price on Repurchase Date (1)(2) Less than 1 year No Repurchase Allowed 1 year 92.5% of Estimated Value per Share 2 years 95.0% of Estimated Value per Share 3 years 97.5% of Estimated Value per Share 4 years 100.0% of Estimated Value per Share In the event of a stockholder’s death or disability (3) Average Issue Price for Shares (4) ________________ (1) As adjusted for any stock dividends, combinations, splits, recapitalizations or any similar transaction with respect to the shares of common stock. (2) For purposes of the share repurchase program, the “Estimated Value per Share” equals the most recently determined estimated value per share determined by the Company’s board of directors. (3) The required one year holding period to be eligible to redeem shares under the Company’s share repurchase program does not apply in the event of death or disability of a stockholder. (4) The purchase price per share for shares redeemed upon the death or disability of a stockholder will be equal to the average issue price per share for all of the stockholder’s shares.

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of Reconciliation of Net Loss Attributable to Common Stockholders and Shares used in Calculating Basic and Diluted Earnings (Loss) Per Share	The following table presents a reconciliation of net loss attributable to common stockholders and shares used in calculating basic and diluted earnings (loss) per share, (“EPS”), for the years ended December 31, 2017 , 2016 and 2015 : Years Ended December 31, 2017 2016 2015 Net income (loss) attributable to the Company $ 72,473,867 $ (25,579,651 ) $ (13,024,358 ) Less: dividends declared on participating securities 9,323 183,805 360,446 Net income (loss) attributable to common stockholders 72,464,544 (25,763,456 ) (13,384,804 ) Weighted average common shares outstanding — basic 75,794,705 76,195,083 76,335,114 Weighted average common shares outstanding — diluted 75,807,710 76,195,083 76,335,114 Earnings (loss) per common share — basic and diluted $ 0.96 $ (0.34 ) $ (0.18 )

Related Party Arrangements (Tab

Related Party Arrangements (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Schedule of Amounts Attributable to the Advisor and its Affiliates	Amounts attributable to the Advisor and its affiliates incurred (received) for the years ended December 31, 2017 , 2016 and 2015 are as follows: Incurred (Received) For the Year Ended December 31, 2017 2016 2015 Consolidated Statements of Operations: Expensed Investment management fees (1) $ 13,823,000 $ 14,075,818 $ 13,854,825 Acquisition fees (1) — 960 187,735 Acquisition expenses (2) — — 7,145 Property management Fees (1) 6,278,850 6,406,479 6,188,525 Reimbursement of onsite personnel (3) 18,716,284 18,751,492 18,760,621 Other fees (1) 1,771,620 1,673,724 1,696,828 Other fees - property operations (3) 170,067 — — Other fees - G&A (4) 133,419 168,037 — Other operating expenses (4) 1,244,264 1,232,493 1,346,002 Disposition fees (5) 6,706,200 — — Disposition transaction costs (5) 56,922 — — Refinancing fee (1) 86,675 3,283,737 — Property insurance (6) 1,285,490 311,794 172,769 Insurance proceeds (7) (102,147 ) (113,853 ) — Consolidated Balance Sheets: Capitalized Construction management Fees (8) 526,866 1,493,999 1,618,438 Reimbursement of labor costs (8) 239,015 367,204 233,748 Capital expenditures (8) 74,709 17,654 3,900 Deferred financing costs (9) 12,930 139,229 — Capitalized costs on investment in unconsolidated joint venture (10) 65,113 — — Acquisition expenses 3,226 — — $ 51,092,503 $ 47,808,767 $ 44,070,536 ________________ (1) Included in fees to affiliates in the accompanying consolidated statements of operations. (2) Included in acquisition costs in the accompanying consolidated statements of operations. (3) Included in operating, maintenance and management in the accompanying consolidated statements of operations. (4) Included in general and administrative expenses in the accompanying consolidated statements of operations. (5) Included in gain on sales of real estate, net in the accompanying consolidated statements of operations. (6) Property related insurance expense and the amortization of the prepaid insurance deductible account are included in general and administrative expenses in the accompanying consolidated statements of operations. The amortization of the prepaid property insurance is included in operating, maintenance and management expenses in the accompanying consolidated statements of operations. The prepaid insurance is included in other assets in the accompanying consolidated balance sheets upon payment. (7) Included in tenant reimbursements and other in the accompanying consolidated statements of operations. (8) Included in building and improvements in the accompanying consolidated balance sheets. (9) Included in mortgage notes payable, net in the accompanying consolidated balance sheets. (10) Included in investment in unconsolidated joint venture in the accompanying consolidated balance sheets. Amounts attributable to the Advisor and its affiliates paid (received) for the years ended December 31, 2017 , 2016 and 2015 are as follows: Paid (Received) For the Year Ended December 31, 2017 2016 2015 Consolidated Statements of Operations: Expensed Investment management fees $ 15,008,001 $ 14,060,587 $ 13,840,067 Acquisition fees — 960 791,135 Acquisition expenses — — 11,147 Property management Fees 6,410,591 6,392,550 6,169,938 Reimbursement of onsite personnel 18,748,974 18,650,009 18,639,991 Other fees 1,781,318 1,671,282 1,721,504 Other fees - property operations 170,067 — — Other fees - G&A 133,419 168,037 — Other operating expenses 1,341,997 1,098,568 1,367,226 Disposition fees 6,139,575 — — Disposition transaction costs 56,922 — — Refinancing fee — 3,283,737 — Property insurance 1,322,247 361,490 247,258 Insurance proceeds (102,147 ) (113,853 ) — Consolidated Balance Sheets: Capitalized Construction management Fees 536,866 1,548,701 1,590,514 Reimbursement of labor costs 245,889 474,155 119,626 Capital expenditures 74,709 17,654 3,900 Deferred financing costs 12,930 139,229 — Capitalized costs on investment in unconsolidated joint venture 65,113 — — Acquisition expenses 3,226 — — $ 51,949,697 $ 47,753,106 $ 44,502,306 Amounts attributable to the Advisor and its affiliates that are payable (prepaid) as of December 31, 2017 and 2016 are as follows: Payable (Prepaid) as of December 31, 2017 2016 Consolidated Statements of Operations: Expensed Investment management fees $ — $ 1,185,001 Acquisition fees — — Acquisition expenses — — Property management Fees 402,315 534,056 Reimbursement of onsite personnel 772,584 805,274 Other fees 44,981 54,679 Other fees - property operations — — Other fees - G&A — — Other operating expenses 87,221 184,954 Disposition fees 566,625 — Disposition transaction costs — — Refinancing fee 86,675 — Property insurance (160,942 ) (124,185 ) Insurance proceeds — — Consolidated Balance Sheets: Capitalized Construction management Fees 6,431 16,431 Reimbursement of labor costs 297 7,171 Capital expenditures — — Deferred financing costs — — Capitalized costs on investment in unconsolidated joint venture — — Acquisition expenses — — $ 1,806,187 $ 2,663,381

Derivative Financial Instrume32

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Interest Rate Derivative Instruments	The following table provides the terms of the Company’s interest rate derivative instruments that were in effect at December 31, 2017 and 2016 : December 31, 2017 Type Maturity Date Range Based on Number of Instruments Notional Amount Variable Rate Weighted Average Rate Cap Fair Value Interest rate cap 1/1/2018 - 10/1/2019 One-Month LIBOR 18 $ 458,655,000 1.56 % 2.89 % $ 51,646 December 31, 2016 Type Maturity Date Range Based on Number of Instruments Notional Amount Variable Rate Weighted Average Rate Cap Fair Value Interest rate cap 4/1/2017 - 10/1/2019 One-Month LIBOR 43 $ 973,400,000 0.77 % 2.70 % $ 618,841

Selected Quarterly Results (u33

Selected Quarterly Results (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Unaudited Quarterly Financial Information	Presented below is a summary of the Company’s unaudited quarterly financial information for the years ended December 31, 2017 and 2016 : First Quarter Second Quarter Third Quarter Fourth Quarter Total 2017 Revenues $ 54,280,265 $ 55,118,406 $ 55,592,107 $ 47,978,462 $ 212,969,240 Net (loss) income (5,644,875 ) (5,656,573 ) (2,326,578 ) 86,101,893 72,473,867 (Loss) income per common share, basic and diluted (0.07 ) (0.07 ) (0.03 ) 1.14 0.96 Distributions declared per common share 0.177 0.179 0.181 0.181 0.718 2016 Revenues $ 52,906,908 $ 54,022,623 $ 56,371,925 $ 54,936,076 $ 218,237,532 Net loss (3,618,142 ) (8,039,220 ) (9,699,187 ) (4,223,102 ) (25,579,651 ) Loss per common share, basic and diluted (0.05 ) (0.11 ) (0.13 ) (0.05 ) (0.34 ) Distributions declared per common share 0.178 0.178 0.180 0.180 0.716

Organization and Business - Nar

Organization and Business - Narrative (Details)	Jul. 10, 2009USD ($)shares	Jun. 12, 2009USD ($)$ / sharesshares	Dec. 31, 2017ft²Investmentapartmentproperty$ / sharesshares	Dec. 31, 2009shares	Nov. 10, 2017apartment	Dec. 31, 2016shares
Class of Stock [Line Items]
Number of multifamily real estate properties owned | property			2
Residential Real Estate [Member]
Class of Stock [Line Items]
Number of multifamily real estate properties owned | property			48
Number of units in real estate property (in number of units or apartments) | apartment			12,156
Commercial Real Estate [Member]
Class of Stock [Line Items]
Number of multifamily real estate properties owned | property			2
Net rentable area (in square feet) | ft²			21,130
Advisor [Member]
Class of Stock [Line Items]
Investment from advisor | $	$ 1,000
Common Stock [Member]
Class of Stock [Line Items]
Share price (in dollars per share) | $ / shares			$ 10.24
Stock issued to advisor (in shares)			75,479,409			76,202,862
Common Stock [Member] | Sponsor [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares)		22,223		22,223
Share price (in dollars per share) | $ / shares		$ 9
Proceeds from issuance of common stock | $		$ 200,007
Convertible Stock [Member]
Class of Stock [Line Items]
Stock issued to advisor (in shares)			1,000			1,000
Convertible Stock [Member] | Advisor [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares)			1,000	1,000
Stock issued to advisor (in shares)	1,000
BREIT Steadfast MF JV LP [Member]
Class of Stock [Line Items]
Ownership percentage			10.00%
Number of units in real estate property (in number of units or apartments) | apartment					20
BREIT Steadfast MF JV LP [Member] | Residential Real Estate [Member]
Class of Stock [Line Items]
Number of multifamily real estate properties owned | property			12
Number of Joint Ventures | Investment			1
Number of units in real estate property (in number of units or apartments) | apartment			3,301

Organization and Business - N35

Organization and Business - Narrative - Private Offering (Details) - USD ($)	9 Months Ended	12 Months Ended
	Jul. 09, 2010	Dec. 31, 2017	Oct. 13, 2009
Common Stock [Member]
Class of Stock [Line Items]
Share price (in dollars per share)		$ 10.24
Private Offering [Member]
Class of Stock [Line Items]
Proceeds from issuance of common stock		$ 2,000,000
Private Offering [Member] | Common Stock [Member]
Class of Stock [Line Items]
Values of shares in private offering, up to			$ 94,000,000
Share price (in dollars per share)			$ 9.4
Issuance of common stock (in shares)	637,279
Proceeds from issuance of common stock	$ 5,844,325

Organization and Business - N36

Organization and Business - Narrative - Public Offering (Details) - USD ($)	6 Months Ended	9 Months Ended	12 Months Ended	41 Months Ended	108 Months Ended
	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 20, 2013	Dec. 31, 2017	Dec. 31, 2015	Dec. 31, 2014	Sep. 10, 2012	Jul. 19, 2010	Jul. 23, 2009
Class of Stock [Line Items]
Common share, distribution rate per share per day, declared (in dollars per share)	$ 0.001958		$ 0.001964
Stock issued during period, dividend reinvestment plan (in shares)					4,073,759
Proceeds from issuance of common stock, dividend reinvestment plan					$ 39,580,847
Distribution Reinvestment Plan [Member]
Class of Stock [Line Items]
Share price (in dollars per share)								$ 9.73		$ 9.5
Common Stock [Member]
Class of Stock [Line Items]
Share price (in dollars per share)					$ 10.24
Common stock, estimated value, per share (in dollars per share)		$ 11.65	$ 11.65			$ 11.44	$ 10.35
Common share, distribution rate per share per day, declared (in dollars per share)		$ 0.001964
Common stock, distribution rate, percentage		7.00%
Common Stock [Member] | Primary Offering [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance, maximum (in shares)									150,000,000
Share price (in dollars per share)									$ 10
Common Stock [Member] | Public Offering [Member]
Class of Stock [Line Items]
Common stock, capital shares reserved for future issuance, distribution reinvestment plan, up to (in shares)									15,789,474
Share price, distribution reinvestment plan (in dollars per share)									$ 9.5
Stock issued during period, shares, new issues (in shares)				73,608,337
Proceeds from issuance of common stock				$ 745,389,748
Common Stock [Member] | Distribution Reinvestment Plan [Member]
Class of Stock [Line Items]
Stock issued during period, dividend reinvestment plan (in shares)				1,588,289
Proceeds from issuance of common stock, dividend reinvestment plan				$ 15,397,232

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Narrative - Reclassifications (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred financing costs	$ (5,109,819)
Payment of debt extinguishment costs	$ 0	$ 3,202,337	$ 0

Summary of Significant Accoun38

Summary of Significant Accounting Policies - Summary of Useful Lives of Assets by Class (Details)	12 Months Ended
	Dec. 31, 2017
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	27 years 6 months
Building Improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Building Improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	25 years
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	10 years

Summary of Significant Accoun39

Summary of Significant Accounting Policies - Narrative - Real Estate Assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Impairment of real estate assets	$ 0	$ 0	$ 0

Summary of Significant Accoun40

Summary of Significant Accounting Policies - Narrative - Revenue Recognition (Details)	12 Months Ended
	Dec. 31, 2017
Maximum [Member]
Operating Leased Assets [Line Items]
Operating lease term	1 year

Summary of Significant Accoun41

Summary of Significant Accounting Policies - Narrative - Restricted Cash (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Restricted cash and cash equivalents	$ 31,442,700	$ 15,466,891
Restricted cash and cash equivalents, held by intermediaries for purposes of facilitating a 1031 exchange	$ 17,197,810	$ 0

Summary of Significant Accoun42

Summary of Significant Accounting Policies - Narrative - Short-term Investments (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Short-term investments	$ 0	$ 30,084,750
Certificates of Deposit [Member]
Schedule of Investments [Line Items]
Short-term investments		30,000,000
Tenant Improvements And Other [Member]
Schedule of Investments [Line Items]
Short-term investments	$ 278,883	$ 84,750

Summary of Significant Accoun43

Summary of Significant Accounting Policies - Summary of Assets Required to be Measured at Fair Value on a Recurring Basis (Details) - Interest Rate Cap [Member] - Fair Value, Measurements, Recurring [Member] - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate cap agreements	$ 0	$ 0
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate cap agreements	51,646	618,841
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate cap agreements	$ 0	$ 0

Summary of Significant Accoun44

Summary of Significant Accounting Policies - Narrative - Fair Value of Financial Instruments (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable, net	$ 683,326,105	$ 683,977,182
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable at fair value	878,004,294	1,197,015,105
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage notes payable, net	$ 875,785,938	$ 1,217,716,280

Summary of Significant Accoun45

Summary of Significant Accounting Policies - Narrative - Distribution Policy (Details) - $ / shares	6 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2016
Accounting Policies [Abstract]
Common share, distribution rate per share per day, declared (in dollars per share)	$ 0.001958	$ 0.001964

Summary of Significant Accoun46

Summary of Significant Accounting Policies - Narrative - Operating Expenses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Other operating expense reimbursement, percentage of average invested assets, threshold	2.00%
Other operating expense reimbursement, percentage of net income, threshold	25.00%
Due to affiliates	$ 1,967,129	$ 2,787,566
Advisor [Member]
Related Party Transaction [Line Items]
Due to affiliates	87,220
Advisor [Member] | General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 4,666,862

Summary of Significant Accoun47

Summary of Significant Accounting Policies - Narrative - Income Taxes (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Liability for uncertain tax positions	$ 0	$ 0

Summary of Significant Accoun48

Summary of Significant Accounting Policies - Narrative - Segment Disclosure (Details)	12 Months Ended
	Dec. 31, 2017segment
Accounting Policies [Abstract]
Number of reportable segments	1

Summary of Significant Accoun49

Summary of Significant Accounting Policies - Narrative - Recent Accounting Pronouncements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred financing costs	$ (5,109,819)
Net cash provided by (used in) operating activities	(47,078,463)	$ (54,259,420)	$ (51,424,087)
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-15 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) operating activities	$ 0	$ 3,202,337	$ 0

Real Estate - Narrative (Detail

Real Estate - Narrative (Details)	12 Months Ended
	Dec. 31, 2017USD ($)ft²apartmentpropertycustomer	Dec. 31, 2016USD ($)customer	Dec. 31, 2015USD ($)
Real Estate Properties [Line Items]
Number of multifamily real estate properties owned | property	2
Purchase price	$ 1,208,240,189
Average percentage of real estate portfolio occupied	93.80%	93.50%
Average monthly collected rent	$ 1,037	$ 1,026
Depreciation and amortization	$ 67,755,152	$ 69,513,484	$ 65,640,196
Customer Concentration Risk [Member] | Tenant [Member]
Real Estate Properties [Line Items]
Number of tenant representing over 10% of Company's annualized base rent | customer	0	0
Accounts Payable and Accrued Liabilities [Member]
Real Estate Properties [Line Items]
Security deposit liability	$ 3,339,602	$ 5,047,792
Maximum [Member]
Real Estate Properties [Line Items]
Operating lease term	1 year
Residential Real Estate [Member]
Real Estate Properties [Line Items]
Number of multifamily real estate properties owned | property	48
Number of units in real estate property (in number of units or apartments) | apartment	12,156
Percentage of units leased	95.40%
Operating leases, revenue, percentage	99.00%	99.00%
Residential Real Estate [Member] | Maximum [Member]
Real Estate Properties [Line Items]
Operating lease term	12 months
Commercial Real Estate [Member]
Real Estate Properties [Line Items]
Number of multifamily real estate properties owned | property	2
Net rentable area (in square feet) | ft²	21,130
Operating leases, revenue, percentage	1.00%	1.00%
Commercial Real Estate [Member] | Minimum [Member]
Real Estate Properties [Line Items]
Operating lease term	1 year 4 months 29 days
Commercial Real Estate [Member] | Maximum [Member]
Real Estate Properties [Line Items]
Operating lease term	7 years 3 months
Building and Improvements [Member]
Real Estate Properties [Line Items]
Depreciation	$ 67,601,984	$ 69,360,316	65,271,243
Tenant Origination and Absorption Cost [Member]
Real Estate Properties [Line Items]
Amortization	$ 0	0	215,786
Weighted-average amortization period	1 year
Other Intangible Assets [Member]
Real Estate Properties [Line Items]
Amortization	$ 153,168	$ 153,168	$ 153,167
Weighted-average amortization period	18 years 2 months 1 day

Real Estate - Schedule of Accum

Real Estate - Schedule of Accumulated Depreciation and Amortization Related to the Consolidated Real Estate Properties and Related Intangibles (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Real Estate Properties [Line Items]
Investments in real estate	$ 1,089,940,499	$ 1,080,543,758
Less: Accumulated depreciation and amortization	(193,075,058)	(147,507,076)
Net investments in real estate and related lease intangibles	896,865,441	933,036,682
Land [Member]
Real Estate Properties [Line Items]
Investments in real estate	115,023,911	114,972,911
Less: Accumulated depreciation and amortization	0	0
Net investments in real estate and related lease intangibles	115,023,911	114,972,911
Building and Improvements [Member]
Real Estate Properties [Line Items]
Investments in real estate	972,272,325	962,926,584
Less: Accumulated depreciation and amortization	(192,375,859)	(146,961,045)
Net investments in real estate and related lease intangibles	779,896,466	815,965,539
Other Intangible Assets [Member]
Real Estate Properties [Line Items]
Investments in real estate	2,644,263	2,644,263
Less: Accumulated depreciation and amortization	(699,199)	(546,031)
Net investments in real estate and related lease intangibles	1,945,064	2,098,232
Real Estate Investment [Member]
Real Estate Properties [Line Items]
Investments in real estate	1,089,940,499	1,080,543,758
Less: Accumulated depreciation and amortization	(193,075,058)	(147,507,076)
Net investments in real estate and related lease intangibles	896,865,441	933,036,682
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Real Estate Investment [Member]
Real Estate Properties [Line Items]
Investments in real estate	158,356,486	613,735,200
Less: Accumulated depreciation and amortization	(28,506,597)	(85,237,007)
Net investments in real estate and related lease intangibles	$ 129,849,889	$ 528,498,193

Real Estate - Schedule of Futur

Real Estate - Schedule of Future Amortization of Acquired Other Intangible Assets (Details) - Other Intangible Assets [Member]	Dec. 31, 2017USD ($)
Finite-Lived Intangible Assets [Line Items]
2,018	$ 153,168
2,019	153,168
2,020	153,168
2,021	153,168
2,022	153,168
Thereafter	1,179,224
Future amortization of acquired other intangible assets	$ 1,945,064

Real Estate - Schedule of Fut53

Real Estate - Schedule of Future Minimum Rental Receipts from Properties under Non-cancelable Operating Leases Attributable to Commercial Office Tenants (Details)	Dec. 31, 2017USD ($)
Real Estate [Abstract]
2,018	$ 259,143
2,019	180,858
2,020	74,313
2,021	76,535
2,022	76,535
Thereafter	185,501
Total future minimum rental receipts	$ 852,885

Real Estate - Joint Venture Arr

Real Estate - Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. (Details)	Jan. 31, 2018apartment_community	Nov. 15, 2017USD ($)apartment_community	Nov. 10, 2017apartment_communityapartment	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	May 16, 2014USD ($)apartment
Schedule of Equity Method Investments [Line Items]
Number of real estate properties acquired							3,301
Payments to acquire real estate | $				$ 16,401,961	$ 28,268,601	$ 29,908,727	$ 318,576,792
Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			4,584
Ownership percent sold		90.00%
Proceeds from sale | $		$ 335,430,000
Gain on sale | $		$ 76,135,530
First Closing Properties [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			3,301
Ashley Oak Apartments [Member] | San Antonio [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			462
Audubon Park [Member] | Nashville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			256
The Belmont [Member] | Dallas [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			260
Indian Lake Village [Member] | Nashville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			206
Cooper Creek Property [Member] | Louisville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			123
Grayson Ridge [Member] | Dallas [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			240
Landing at Mansfield [Member] | Dallas [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			336
Meritage at Steiner Ranch [Member] | Austin [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			502
Montelena Property [Member] | Austin [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			232
Richland Falls [Member] | Nashville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			276
Rosemont at Olmos Park [Member] | San Antonio [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			144
The Trails at Buda Ranch [Member] | Austin [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			264
Second Closing Properties [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			1,283
Arbors At Carrollton [Member] | Dallas [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			131
The Hills at Fair Oaks [Member] | San Antonio [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			288
Keystone Farms Property [Member] | Nashville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			90
Renaissance St. Andrews [Member] | Louisville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			216
Renaissance St. Andrews Condominiums [Member] | Louisville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			30
Springmarc Property [Member] | Austin [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			240
Valley Farms Property [Member] | Louisville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			160
Valley Farms North Property [Member] | Louisville [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed			128
SIR Land Holdings, LLC [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed | apartment_community		12	20
Ownership percentage			10.00%
BREIT LP [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage			90.00%
Subsequent Event [Member] | SIR Land Holdings, LLC [Member] | Joint Venture Arrangement with Blackstone Real Estate Income Trust, Inc. [Member]
Schedule of Equity Method Investments [Line Items]
Number of properties contributed | apartment_community	8

Real Estate - Property Disposit

Real Estate - Property Dispositions (Details)	Dec. 15, 2017USD ($)	Dec. 13, 2017USD ($)	Oct. 30, 2017USD ($)	Sep. 29, 2017USD ($)	Sep. 12, 2014USD ($)apartment	Dec. 13, 2013USD ($)apartment	Apr. 30, 2013USD ($)apartment	Jan. 26, 2012USD ($)apartment	Dec. 22, 2010USD ($)apartment	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rental income																		$ 188,019,112	$ 192,088,348	$ 186,264,470
Tenant reimbursements and other																		24,950,128	26,149,184	23,126,188
Total revenues										$ 47,978,462	$ 55,592,107	$ 55,118,406	$ 54,280,265	$ 54,936,076	$ 56,371,925	$ 54,022,623	$ 52,906,908	212,969,240	218,237,532	209,390,658
Operating, maintenance and management																		58,347,903	57,832,187	53,915,306
Real estate taxes and insurance																		35,114,937	36,507,827	35,825,445
Fees to affiliates																		21,960,145	25,440,718	21,927,913
Depreciation and amortization																		67,755,152	69,513,484	65,640,196
Interest expense																		44,114,130	40,551,427	39,149,018
Loss on debt extinguishment																		(2,380,051)	(4,932,369)	0
General and administrative expenses																		6,732,330	9,039,171	5,949,993
Total expenses																		236,404,648	243,817,183	222,415,016
Discontinued Operations, Disposed of by Sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Rental income																		46,450,562	51,585,026	49,329,436
Tenant reimbursements and other																		6,383,148	7,090,653	6,330,963
Total revenues																		52,833,710	58,675,679	55,660,399
Operating, maintenance and management																		15,863,468	16,579,083	15,338,184
Real estate taxes and insurance																		10,162,131	10,634,970	11,065,115
Fees to affiliates																		2,087,374	2,260,569	2,171,583
Depreciation and amortization																		16,659,338	19,022,464	17,830,725
Interest expense																		10,406,061	9,372,856	8,230,556
Loss on debt extinguishment																		2,387,552	1,495,312	0
General and administrative expenses																		561,437	1,175,433	337,469
Total expenses																		$ 58,127,361	$ 60,540,687	$ 54,973,632
Discontinued Operations, Disposed of by Sale [Member] | Park Place Property [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment homes acquired | apartment									151
Cost of acquired units									$ 8,323,400
Consideration				$ 10,325,000
Gross profit (loss)				3,455,608
Discontinued Operations, Disposed of by Sale [Member] | Windsor on the River Property [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment homes acquired | apartment								424
Cost of acquired units								$ 33,000,000
Consideration				29,750,000
Gross profit (loss)				$ 1,927,239
Discontinued Operations, Disposed of by Sale [Member] | Renaissance at Carol Stream [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment homes acquired | apartment						293
Cost of acquired units						$ 29,150,000
Consideration			$ 33,900,000
Gross profit (loss)			$ 6,688,979
Discontinued Operations, Disposed of by Sale [Member] | Deer Valley Apartments [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment homes acquired | apartment							224
Cost of acquired units							$ 28,600,000
Consideration		$ 31,075,000
Gross profit (loss)		$ 5,502,148
Discontinued Operations, Disposed of by Sale [Member] | Park Shore Apartments [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of apartment homes acquired | apartment					160
Cost of acquired units					$ 18,350,000
Consideration	$ 20,100,000
Gross profit (loss)	$ 2,863,667

Real Estate - Schedule of Real

Real Estate - Schedule of Real Estate Held for Sale (Details) - The Moorings Apartments, Arrowhead Apartment Homes and The Second Closing Properties [Member] - Discontinued Operations, Held-for-sale [Member] - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues	$ 21,889,939	$ 21,257,326	$ 19,748,536
Expenses	19,926,810	20,705,376	19,322,136
Total Income	$ 1,963,129	$ 551,950	$ 426,400

Investment in Unconsolidated 57

Investment in Unconsolidated Joint Venture - Narrative (Details) - BREIT Steadfast MF JV LP [Member]	Nov. 10, 2017apartment	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)
Schedule of Equity Method Investments [Line Items]
Number of units in real estate property (in number of units or apartments) | apartment	20
Noncash or Part Noncash Acquisition, Interest Acquired	10.00%
Book value of joint venture		$ 8,133,156	$ 8,133,156
Outside difference		5,515,754	5,515,754
Amortization of the basis difference		$ 106,519	$ 106,519
BREIT LP [Member]
Schedule of Equity Method Investments [Line Items]
Noncash or Part Noncash Acquisition, Interest Acquired	90.00%

Investment in Unconsolidated 58

Investment in Unconsolidated Joint Venture - Schedule of Financial Information of Joint Venture (Details) - USD ($)	2 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Company's Proportional Share:
Equity in loss of unconsolidated joint venture		$ (663,896)	$ 0	$ 0
BREIT Steadfast MF JV LP [Member]
Assets:
Real estate assets, net	$ 374,277,205	374,277,205
Other assets	15,328,440	15,328,440
Total assets	389,605,645	389,605,645
Liabilities and equity:
Notes payable, net	264,558,057	264,558,057
Other liabilities	11,525,292	11,525,292
Company’s capital	11,352,230	11,352,230
Other partner’s capital	102,170,066	102,170,066
Total liabilities and equity	389,605,645	389,605,645
Income Statement:
Revenues	5,756,455
Expenses	11,330,228
Net loss	(5,573,773)
Company's Proportional Share:
Company’s proportional net loss	(557,377)
Amortization of outside basis	(106,519)	$ (106,519)
Equity in loss of unconsolidated joint venture	$ (663,896)

Other Assets - Other Assets (De

Other Assets - Other Assets (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid expenses	$ 2,132,212	$ 3,041,353
Interest rate cap agreements	51,646	618,841
Deposits	1,074,726	1,126,568
Other assets	$ 3,258,584	$ 4,786,762

Debt - Summary of Notes Payable

Debt - Summary of Notes Payable Secured by Real Property (Details)	12 Months Ended
	Dec. 31, 2017USD ($)instrument	Dec. 31, 2016USD ($)instrument
Debt Instrument [Line Items]
Principal Outstanding	$ 683,326,105	$ 683,977,182
Deferred financing costs	(5,109,819)
Total notes payable, net	$ 875,785,938	$ 1,217,716,280
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Number of Instruments | instrument	46	58
Weighted Average Interest Rate	3.87%	3.52%
Principal Outstanding	$ 789,154,854	$ 989,229,820
Unamortized Portion of Net Debt Premium	673,653	2,208,619
Deferred financing costs	(4,264,667)	(6,358,285)
Total notes payable, net	$ 785,563,840	$ 985,080,154
Notes Payable to Banks [Member] | Mortgage Notes Payable, Fixed Interest [Member]
Debt Instrument [Line Items]
Number of Instruments | instrument	32	37
Weighted Average Interest Rate	3.89%	4.06%
Principal Outstanding	$ 416,673,854	$ 471,344,145
Notes Payable to Banks [Member] | Mortgage Notes Payable, Fixed Interest [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.19%	3.19%
Notes Payable to Banks [Member] | Mortgage Notes Payable, Fixed Interest [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.75%	5.94%
Notes Payable to Banks [Member] | Mortgage Notes Payable, Variable Interest [Member]
Debt Instrument [Line Items]
Number of Instruments | instrument	14	21
Weighted Average Interest Rate	3.86%	3.05%
Principal Outstanding	$ 372,481,000	$ 517,885,675
Notes Payable to Banks [Member] | Mortgage Notes Payable, Variable Interest [Member] | LIBOR [Member] | Minimum [Member]
Debt Instrument [Line Items]
Variable Rate	2.02%	1.65%
Notes Payable to Banks [Member] | Mortgage Notes Payable, Variable Interest [Member] | LIBOR [Member] | Maximum [Member]
Debt Instrument [Line Items]
Variable Rate	2.50%	2.65%

Debt - Summary of Debt Premiums

Debt - Summary of Debt Premiums and Discounts (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Amortization of Net Debt Premium	$ 1,129,960	$ 1,243,385	$ 1,234,793
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Unamortized Portion of Net Debt Premium	673,653	2,208,619
Amortization of Net Debt Premium	$ 1,129,960	$ 1,243,385	$ 1,234,793

Debt - Summary of Deferred Fina

Debt - Summary of Deferred Finance Costs (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Deferred financing costs, net	$ 5,109,819
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Deferred financing costs	8,215,716	$ 10,104,244
Accumulated amortization related to deferred financing costs	(3,951,049)	(3,745,959)
Deferred financing costs, net	$ 4,264,667	$ 6,358,285

Debt - Narrative (Details)

Debt - Narrative (Details)	Jul. 29, 2016USD ($)subsidiary	Jun. 30, 2016USD ($)subsidiary	Jul. 18, 2014USD ($)	Jul. 17, 2014USD ($)	Sep. 29, 2016USD ($)subsidiary	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Debt Instrument [Line Items]
Revolving credit facility						$ 90,222,098	$ 88,578,626
Interest expense						44,114,130	40,631,593	$ 39,302,938
Amortization of deferred financing costs						1,839,952	1,723,186	1,553,718
Amortization of debt premium (discount)						1,129,960	1,243,385	1,234,793
Unrealized loss on derivatives						604,545	(61,698)	2,032,746
Interest paid, net of amounts capitalized of $0, $80,166 and $153,920 for the years ended December 31, 2017, 2016 and 2015, respectively						0	80,166	153,920
Real Estate [Member]
Debt Instrument [Line Items]
Interest paid, net of amounts capitalized of $0, $80,166 and $153,920 for the years ended December 31, 2017, 2016 and 2015, respectively						0	80,166	153,920
Accounts Payable and Accrued Liabilities [Member]
Debt Instrument [Line Items]
Interest payable						2,766,036	3,444,162
Interest Rate Cap [Member]
Debt Instrument [Line Items]
Unrealized loss on derivatives						604,545	(61,698)	2,032,746
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Number of subsidiaries involved as borrowers on debt | subsidiary	9	14			3
Amortization of debt premium (discount)						1,129,960	1,243,385	$ 1,234,793
Extinguishment of debt, amount		$ 283,313,677			$ 61,575,025
Notes Payable to Banks [Member] | Refinancing Transactions Loan Agreement [Member]
Debt Instrument [Line Items]
Face amount		$ 358,002,000			$ 63,620,600
Notes Payable to Banks [Member] | Refinancing Transactions Loan Agreement [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.31%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility						$ 0	$ 0
Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.05%
Maximum borrowing capacity	$ 350,000,000
Payments for loans and leases	1,293,186
Fees and commissions	$ 1,175,624
Revolving Credit Facility [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 35,000,000	$ 20,000,000
Line of credit facility, commitment fee				0.25%
Revolving Credit Facility [Member] | Line of Credit [Member] | Revolving Credit Facility, Tranche A [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 20,000,000
Revolving Credit Facility [Member] | Line of Credit [Member] | Revolving Credit Facility, Tranche A [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.60%
Revolving Credit Facility [Member] | Line of Credit [Member] | Revolving Credit Facility, Tranche A [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			0.75%
Revolving Credit Facility [Member] | Line of Credit [Member] | Revolving Credit Facility, Tranche B [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 15,000,000
Revolving Credit Facility [Member] | Line of Credit [Member] | Revolving Credit Facility, Tranche B [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			3.00%
Revolving Credit Facility [Member] | Line of Credit [Member] | Revolving Credit Facility, Tranche B [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			2.00%
Minimum [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.73%
Maximum [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.93%

Debt - Schedule of Advances Und

Debt - Schedule of Advances Under Credit Facility, by Property (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Subtotal	$ 880,222,104
Total notes payable, net	875,785,938	$ 1,217,716,280
Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	91,067,250	235,124,750
Deferred financing costs, net on credit facility	(845,152)	(2,488,624)
Total notes payable, net	90,222,098	232,636,126
Accumulated amortization related to deferred financing costs	(390,241)	(433,522)
Ashley Oak Apartments [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	0	24,867,500
The Trails at Buda Ranch [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	0	21,025,000
Deer Valley Apartments [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	0	22,982,500
Carrington Park at Huffmeister [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	20,430,500	20,430,500
Carrington Place [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	27,535,500	27,535,500
Carrington at Champion Forest [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	25,121,250	25,121,250
Audubon Park [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	0	16,602,500
Oak Crossing [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	17,980,000	17,980,000
Meritage at Steiner Ranch [Member] | Revolving Credit Facility [Member] | Refinanced PNC Bank Credit Facility [Member]
Debt Instrument [Line Items]
Subtotal	$ 0	$ 58,580,000

Debt - Summary of Aggregate Mat

Debt - Summary of Aggregate Maturities (Details)	Dec. 31, 2017USD ($)
Debt Disclosure [Abstract]
Total	$ 880,222,104
2,018	61,059,734
2,019	100,037,883
2,020	71,298,949
2,021	123,518,437
2,022	34,615,399
Thereafter	$ 489,691,702

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative - General (Details) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Common and preferred stock, shares authorized (in shares)	1,100,000,000
Preferred stock, shares authorized (in shares)	100,000,000	100,000,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	999,999,000	999,999,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Convertible Stock [Member]
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	1,000	1,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01

Stockholders' Equity - Narrat67

Stockholders' Equity - Narrative - Common Stock (Details)	Jun. 11, 2014USD ($)$ / sharesshares	Jun. 12, 2009$ / sharesshares	Dec. 31, 2017USD ($)installments$ / shares	Dec. 31, 2016USD ($)vote / shares	Dec. 31, 2015USD ($)	Dec. 31, 2009USD ($)shares	Dec. 31, 2017USD ($)$ / sharesshares
Class of Stock [Line Items]
Common stock, votes per share | vote / shares				1
Issuance of common stock			$ 0	$ 0	$ 78
Stock issued during period, dividend reinvestment plan (in shares) | shares							4,073,759
Proceeds from issuance of common stock, dividend reinvestment plan							$ 39,580,847
Share-based compensation			85,486	76,285	184,350
Change in value of restricted common stock to Advisor			0	312,353	$ 300,440
Advisor [Member] | Advisor [Member]
Class of Stock [Line Items]
Fair value of shares of common stock (in shares)			$ 5,637,207.03125	$ 5,637,207			5,637,207.03125
Advisor [Member] | Restricted Stock Agreement [Member] | Advisor [Member]
Class of Stock [Line Items]
Issuance of restricted common stock to advisor (in shares) | shares	488,281.25
Issuance of restricted common stock to Advisor	$ 5,000,000
Restricted Stock [Member]
Class of Stock [Line Items]
Weighted-average remaining term			1 year 6 months 2 days
Compensation expense related to issuance of restricted common stock not vested			$ 107,002				107,002
Restricted Stock [Member] | Advisor [Member] | Tranche One [Member] | Advisor [Member]
Class of Stock [Line Items]
Shares of restricted stock vesting percentage	50.00%
Restricted Stock [Member] | Advisor [Member] | Tranche Two [Member] | Advisor [Member]
Class of Stock [Line Items]
Shares of restricted stock vesting percentage	50.00%
Restricted Stock [Member] | Advisor [Member] | Restricted Stock Agreement [Member] | Advisor [Member]
Class of Stock [Line Items]
Share price (in dollars per share) | $ / shares	$ 10.24
Restricted Stock [Member] | Advisor [Member] | Restricted Stock Agreement [Member] | Tranche One [Member] | Advisor [Member]
Class of Stock [Line Items]
Shares of restricted stock vesting percentage					50.00%
Restricted Stock [Member] | Advisor [Member] | Restricted Stock Agreement [Member] | Tranche Two [Member] | Advisor [Member]
Class of Stock [Line Items]
Shares of restricted stock vesting percentage				50.00%
Restricted Stock [Member] | General and Administrative Expense [Member]
Class of Stock [Line Items]
Share-based compensation			85,486	$ 76,285	$ 184,350
Restricted Stock [Member] | General and Administrative Expense [Member] | Advisor [Member] | Advisor [Member]
Class of Stock [Line Items]
Change in value of restricted common stock to Advisor			$ 0	$ 312,353	$ 300,440
Restricted Stock [Member] | Director [Member]
Class of Stock [Line Items]
Restricted common stock, vesting installments | installments			4
Shares of restricted stock vesting percentage			25.00%
Private Offering and Public Offering [Member]
Class of Stock [Line Items]
Commissions on sales of common stock and related dealer manager fees to affiliates							$ 95,845,468
Common Stock [Member]
Class of Stock [Line Items]
Share price (in dollars per share) | $ / shares			$ 10.24				$ 10.24
Common Stock [Member] | Sponsor [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares) | shares		22,223				22,223
Issuance of common stock						$ 200,007
Share price (in dollars per share) | $ / shares		$ 9
Common Stock [Member] | Private Offering and Public Offering [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares) | shares							76,732,395
Proceeds from Issuance of Common Stock, Net of Offering Costs							$ 679,572,220

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Restricted Stock Issued to Independent Directors as Compensation (Details) - Restricted Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested shares at the beginning of the year (in shares)	11,875	11,250	16,875
Granted shares (in shares)	7,500	7,500	14,000
Vested shares (in shares)	(7,500)	(6,875)	(19,625)
Nonvested shares at the end of the year (in shares)	11,875	11,875	11,250
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Weighted Average Fair Value (in dollars per share)	$ 11.65	$ 11.44	$ 10.35

Stockholders' Equity - Narrat69

Stockholders' Equity - Narrative - Convertible Stock (Details)	12 Months Ended
	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2009shares
Class of Stock [Line Items]
Issuance of common stock	$ 0	$ 0	$ 78
Advisor [Member] | Convertible Stock [Member]
Class of Stock [Line Items]
Issuance of common stock (in shares) | shares	1,000			1,000
Aggregate percentage of cumulative, non-compounded, annual return on the original issue price added to total distributions qualifying for conversion of stock		8.00%
Convertible stock, conversion basis, multiplier	0.001
Convertible stock, percentage applied to the excess of enterprise value, including distributions to date		10.00%
Advisor [Member] | Advisor [Member] | Convertible Stock [Member]
Class of Stock [Line Items]
Convertible stock, redemption amount	$ 1

Stockholders' Equity - Narrat70

Stockholders' Equity - Narrative - Preferred Stock (Details)	12 Months Ended
	Dec. 31, 2016classshares	Dec. 31, 2017shares
Equity [Abstract]
Preferred stock, number of classes or series the Board of Directors is authorized to classify or reclassify | class	1
Preferred stock, number of classes or series the Board of Directors is authorized to issue | class	1
Preferred stock, shares issued (in shares) | shares	0	0
Preferred stock, shares outstanding (in shares) | shares	0	0

Stockholders' Equity - Narrat71

Stockholders' Equity - Narrative - Distribution Reinvestment Plan (Details) - Distribution Reinvestment Plan [Member] - USD ($)	Sep. 30, 2016	Sep. 10, 2012	Jul. 23, 2009
Class of Stock [Line Items]
Share price (in dollars per share)		$ 9.73	$ 9.5
Sales commissions and dealer manager fees payable	$ 0

Stockholders' Equity - Narrat72

Stockholders' Equity - Narrative - Share Repurchase Plan and Redeemable Common Stock (Details) - Share Repurchase Plan [Member]	Aug. 09, 2016USD ($)	Jul. 01, 2015USD ($)	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)assetshares	Sep. 30, 2016shares
Class of Stock [Line Items]
Number of company assets sold that constitute a return of capital as a result of such sale. | asset				1
Maximum value of shares allowed to be repurchased per quarter	$ 2,000,000	$ 1,000,000
Notice period for amendment, suspension, or termination of stock repurchase plan.			30 days
Common Stock [Member]
Class of Stock [Line Items]
Number of shares that can be repurchased before the first anniversary of date of purchase | shares					0
Share repurchase plan, disability or death holding period exemption period, maximum				2 years
Stock repurchase plan, minimum redemption notice period			15 days
Stock repurchase plan, settlement period			30 days
Minimum number of days prior to repurchase date a repurchase request may be withdrawn				3 days
Shares redeemed (in shares) | shares			730,953	479,147
Stock repurchase plan, stock redeemed, value			$ 8,000,000	$ 5,000,000
Stock requested for redemption (in shares) | shares			2,521,337	1,335,407
Stock requested for redemption, value			$ 28,904,491	$ 14,625,190
Stock requested for redemption, outstanding (in shares) | shares			3,100,720	1,310,337
Stock requested for redemption, redemptions payable			$ 36,198,922	$ 14,709,973
Maximum percentage of weighted average shares outstanding in prior calendar period that may be repurchased in current calendar period			5.00%
Common Stock [Member] | Accounts Payable and Accrued Liabilities [Member]
Class of Stock [Line Items]
Stock requested for redemption, redemptions payable			$ 2,000,000
Maximum [Member]
Class of Stock [Line Items]
Maximum value of shares allowed to be repurchased per quarter		$ 2,000,000

Stockholders' Equity - Schedu73

Stockholders' Equity - Schedule of Repurchase Prices Under Share Repurchase Plan (Details)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Less than 1 year	0.00%
1 year	92.50%
2 years	95.00%
3 years	97.50%
4 years	100.00%

Stockholders' Equity - Schedu74

Stockholders' Equity - Schedule of Repurchase Prices Under Share Repurchase Plan (Footnote) (Details)	12 Months Ended
	Dec. 31, 2016
Share Repurchase Plan [Member] | Common Stock [Member]
Class of Stock [Line Items]
Required holding period to be eligible to redeem shares under share repurchase plan	1 year

Stockholders' Equity - Narrat75

Stockholders' Equity - Narrative - Distributions (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Deferred costs	$ 0	$ 0

Stockholders' Equity - Narrat76

Stockholders' Equity - Narrative - Distributions Declared (Details) - USD ($)	6 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Common share, distribution rate per share per day, declared (in dollars per share)	$ 0.001958			$ 0.001964
Distributions declared			$ 54,339,823	$ 54,828,267	$ 55,076,217
Distributions payable		$ 4,625,355	$ 4,595,301	4,625,355
Common Stock [Member]
Class of Stock [Line Items]
Common share, distribution rate per share per day, declared (in dollars per share)		$ 0.001964
Common stock, distribution rate, percentage		7.00%
Share price (in dollars per share)			$ 10.24
Distributions declared			$ 54,339,823	54,828,267
Distributions payable		$ 4,625,355	$ 4,595,301	$ 4,625,355

Stockholders' Equity - Narrat77

Stockholders' Equity - Narrative - Distributions Paid (Details) - USD ($)	12 Months Ended			108 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Class of Stock [Line Items]
Payments of ordinary dividends, common stock	$ 54,369,877	$ 54,871,173	$ 55,087,333
Stock issued during period, dividend reinvestment plan (in shares)				4,073,759
Proceeds from issuance of common stock, dividend reinvestment plan				$ 39,580,847

Earnings (Loss) Per Share - Sch

Earnings (Loss) Per Share - Schedule of Reconciliation of Net Loss Attributable to Common Stockholders and Shares used in Calculating Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net income (loss) attributable to the Company	$ 86,101,893	$ (2,326,578)	$ (5,656,573)	$ (5,644,875)	$ (4,223,102)	$ (9,699,187)	$ (8,039,220)	$ (3,618,142)	$ 72,473,867	$ (25,579,651)	$ (13,024,358)
Less: dividends declared on participating securities									9,323	183,805	360,446
Net income (loss) attributable to common stockholders									$ 72,464,544	$ (25,763,456)	$ (13,384,804)
Weighted average number of common shares outstanding — basic (in shares)									75,794,705	76,195,083	76,335,114
Weighted average number of common shares outstanding — diluted (in shares)									75,807,710	76,195,083	76,335,114
Loss per common share - basic and diluted (in dollars per share)	$ 1.14	$ (0.03)	$ (0.07)	$ (0.07)	$ (0.05)	$ (0.13)	$ (0.11)	$ (0.05)	$ 0.96	$ (0.34)	$ (0.18)

Related Party Arrangements - Sc

Related Party Arrangements - Schedule of Amounts Attributable to the Advisor and its Affiliates - Amounts Incurred, Paid, and Payable (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Steadfast Income Advisor, LLC [Member] | General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Incurred in the period	$ 4,666,862
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member]
Related Party Transaction [Line Items]
Incurred in the period	51,092,503	$ 47,808,767	$ 44,070,536
Paid in the period	51,949,697	47,753,106	44,502,306
Payable (Prepaid) at the end of the period	1,806,187	2,663,381
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Investment Management Fees [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	0	1,185,001
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Acquisition Fees [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Acquisition Expenses [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Property Management, Fees [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	402,315	534,056
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Property Management, Reimbursement of Onsite Personnel [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	772,584	805,274
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Property Management, Other Fees [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	44,981	54,679
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Property Management, Other Fees, Property Operations [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Property Management, Other Fees, General and Administrative [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Other Operating Expenses [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	87,221	184,954
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Disposition Fees [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	566,625	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Disposition Transaction Costs [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Refinancing Fee [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	86,675	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Prepaid Insurance Deductible Account [Member]
Related Party Transaction [Line Items]
Incurred in the period	1,285,490	311,794	172,769
Paid in the period	1,322,247	361,490	247,258
Payable (Prepaid) at the end of the period	(160,942)	(124,185)
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Insurance Proceeds [Member]
Related Party Transaction [Line Items]
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Construction Management Fees [Member]
Related Party Transaction [Line Items]
Incurred in the period	526,866	1,493,999	1,618,438
Paid in the period	536,866	1,548,701	1,590,514
Payable (Prepaid) at the end of the period	6,431	16,431
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Construction Management Reimbursement of Labor Costs [Member]
Related Party Transaction [Line Items]
Incurred in the period	239,015	367,204	233,748
Paid in the period	245,889	474,155	119,626
Payable (Prepaid) at the end of the period	297	7,171
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Capital Expenditures [Member]
Related Party Transaction [Line Items]
Incurred in the period	74,709	17,654	3,900
Paid in the period	74,709	17,654	3,900
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Deferred Financing Costs [Member]
Related Party Transaction [Line Items]
Incurred in the period	12,930	139,229	0
Paid in the period	12,930	139,229	0
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Capitalized Costs on Investment in Unconsolidated Joint Venture [Member]
Related Party Transaction [Line Items]
Incurred in the period	65,113	0	0
Paid in the period	65,113	0	0
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Capitalized Acquisition Expenses [Member]
Related Party Transaction [Line Items]
Incurred in the period	3,226	0	0
Paid in the period	3,226	0	0
Payable (Prepaid) at the end of the period	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Fees to Affiliates [Member] | Investment Management Fees [Member]
Related Party Transaction [Line Items]
Incurred in the period	13,823,000	14,075,818	13,854,825
Paid in the period	15,008,001	14,060,587	13,840,067
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Fees to Affiliates [Member] | Acquisition Fees [Member]
Related Party Transaction [Line Items]
Incurred in the period	0	960	187,735
Paid in the period	0	960	791,135
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Fees to Affiliates [Member] | Property Management, Fees [Member]
Related Party Transaction [Line Items]
Incurred in the period	6,278,850	6,406,479	6,188,525
Paid in the period	6,410,591	6,392,550	6,169,938
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Fees to Affiliates [Member] | Property Management, Other Fees [Member]
Related Party Transaction [Line Items]
Incurred in the period	1,771,620	1,673,724	1,696,828
Paid in the period	1,781,318	1,671,282	1,721,504
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Fees to Affiliates [Member] | Property Management, Other Fees, Property Operations [Member]
Related Party Transaction [Line Items]
Incurred in the period	170,067	0	0
Paid in the period	170,067	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Fees to Affiliates [Member] | Property Management, Other Fees, General and Administrative [Member]
Related Party Transaction [Line Items]
Incurred in the period	133,419	168,037	0
Paid in the period	133,419	168,037	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Fees to Affiliates [Member] | Disposition Transaction Costs [Member]
Related Party Transaction [Line Items]
Incurred in the period	56,922	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Acquisition Costs [Member] | Acquisition Expenses [Member]
Related Party Transaction [Line Items]
Incurred in the period	0	0	7,145
Paid in the period	0	0	11,147
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Operating, Maintenance and Management [Member] | Property Management, Reimbursement of Onsite Personnel [Member]
Related Party Transaction [Line Items]
Incurred in the period	18,716,284	18,751,492	18,760,621
Paid in the period	18,748,974	18,650,009	18,639,991
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | General and Administrative Expense [Member] | Other Operating Expenses [Member]
Related Party Transaction [Line Items]
Incurred in the period	1,244,264	1,232,493	1,346,002
Paid in the period	1,341,997	1,098,568	1,367,226
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | General and Administrative Expense [Member] | Refinancing Fee [Member]
Related Party Transaction [Line Items]
Incurred in the period	86,675	3,283,737	0
Paid in the period	0	3,283,737	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | General and Administrative Expense [Member] | Insurance Proceeds [Member]
Related Party Transaction [Line Items]
Incurred in the period	102,147	113,853	0
Paid in the period	(102,147)	(113,853)	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Sales of Real Estate [Member] | Disposition Fees [Member]
Related Party Transaction [Line Items]
Incurred in the period	6,706,200	0	0
Paid in the period	6,139,575	0	0
Steadfast Income Advisor, LLC [Member] | Advisor and its Affiliates [Member] | Sales of Real Estate [Member] | Disposition Transaction Costs [Member]
Related Party Transaction [Line Items]
Paid in the period	$ 56,922	$ 0	$ 0

Related Party Arrangements - Na

Related Party Arrangements - Narrative - Investment Management Fee (Details)	12 Months Ended
	Dec. 31, 2017
Advisor [Member] | Advisor [Member] | Investment Management Fees [Member]
Related Party Transaction [Line Items]
Monthly investment management fee, percentage	0.06667%

Related Party Arrangements - 81

Related Party Arrangements - Narrative - Acquisition Fees and Expenses (Details) - Advisor [Member] - Advisor [Member] - Acquisition Fees and Expenses [Member]	12 Months Ended
	Dec. 31, 2017
Related Party Transaction [Line Items]
Acquisition fee, percentage of purchase price of real property or related asset	2.00%
Acquisition fees and expenses, maximum, percentage of contract purchase price	6.00%

Related Party Arrangements - 82

Related Party Arrangements - Narrative - Property Management Fees and Expenses (Details) - Steadfast Management Company, Inc. [Member] - Property Management Agreement [Member]	12 Months Ended
	Dec. 31, 2017
Related Party Transaction [Line Items]
Property management agreement, notice of termination breach	30 days
Property Manager [Member]
Related Party Transaction [Line Items]
Property management, oversight fee, percent	1.00%
Property management agreement, initial term	1 year
Property management agreement, notice of termination option	60 days
Property Manager [Member] | Minimum [Member]
Related Party Transaction [Line Items]
Property management fee, percent	2.50%
Property Manager [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Property management fee, percent	3.75%

Related Party Arrangements - 83

Related Party Arrangements - Narrative - Construction Management (Details) - Pacific Coast Land & Construction, Inc. [Member] - Affiliated Entity [Member] - Construction Management Agreement [Member]	12 Months Ended
	Dec. 31, 2017
Related Party Transaction [Line Items]
Construction management agreement, termination notification period	30 days
Minimum [Member]
Related Party Transaction [Line Items]
Construction management fee, percent	5.00%
Maximum [Member]
Related Party Transaction [Line Items]
Construction management fee, percent	12.00%

Related Party Arrangements - 84

Related Party Arrangements - Narrative - Other Operating Expense Reimbursements (Details)	12 Months Ended
	Dec. 31, 2017USD ($)quarter	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Related Party Transaction [Line Items]
Other operating expense reimbursement, percentage of average invested assets, threshold	2.00%
Other operating expense reimbursement, percentage of net income, threshold	25.00%
Operating expenses	$ 236,404,648	$ 243,817,183	$ 222,415,016
Other Operating Expense Reimbursement [Member]
Related Party Transaction [Line Items]
General and administrative expenses	$ 6,732,330	9,039,171	5,949,993
Operating expenses, percent of average invested assets	0.10%
Operating expenses, percent of net loss	1.70%
Other Operating Expense Reimbursement [Member] | Advisor and its Affiliates [Member]
Related Party Transaction [Line Items]
Operating expenses	$ 1,244,264	1,232,493	1,346,002
Overhead expenses	1,244,264	1,232,493	1,346,002
Related party transaction, expenses from transactions with related party	$ 0	$ 0	$ 0
Advisor [Member] | Advisor [Member] | Other Operating Expense Reimbursement [Member]
Related Party Transaction [Line Items]
Operating expenses limited, number of quarters | quarter	4
Other operating expense reimbursement, percentage of average invested assets, threshold	2.00%
Other operating expense reimbursement, percentage of net income, threshold	25.00%
Average invested assets, calculation period	12 months

Related Party Arrangements - 85

Related Party Arrangements - Narrative - Disposition Fee (Details)	12 Months Ended
	Dec. 31, 2017$ / shares
Related Party Transaction [Line Items]
Other operating expense reimbursement, percentage of average invested assets, threshold	2.00%
Other operating expense reimbursement, percentage of net income, threshold	25.00%
Advisor [Member] | Advisor [Member] | Disposition Fee [Member]
Related Party Transaction [Line Items]
Disposition fee, percent of sales price	1.50%
Disposition fee, maximum, percentage of sales price	3.00%
Acquisition fees and expenses, maximum, percentage of contract purchase price	6.00%
Disposition fee, maximum brokerage commission paid, percent	50.00%
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 1 [Member]
Related Party Transaction [Line Items]
Disposition fee, percent of sales price	0.50%
Share price (in dollars per share)	$ 9
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 2 [Member]
Related Party Transaction [Line Items]
Disposition fee, percent of sales price	0.75%
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 2 [Member] | Minimum [Member]
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 9.01
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 2 [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 10.24
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 3 [Member]
Related Party Transaction [Line Items]
Disposition fee, percent of sales price	1.00%
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 3 [Member] | Minimum [Member]
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 10.25
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 3 [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 11.24
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 4 [Member]
Related Party Transaction [Line Items]
Disposition fee, percent of sales price	1.25%
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 4 [Member] | Minimum [Member]
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 11.25
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 4 [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 12
Advisor [Member] | Advisor [Member] | Disposition Fee, Range 5 [Member]
Related Party Transaction [Line Items]
Disposition fee, percent of sales price	1.50%
Share price (in dollars per share)	$ 12.01
Advisor [Member] | Advisor [Member] | Other Operating Expenses [Member]
Related Party Transaction [Line Items]
Other operating expense reimbursement, percentage of average invested assets, threshold	2.00%
Other operating expense reimbursement, percentage of net income, threshold	25.00%

Related Party Arrangements - 86

Related Party Arrangements - Narrative - Refinancing Fees (Details) - Steadfast Income Advisor, LLC [Member] - Advisor and its Affiliates [Member] - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 51,092,503	$ 47,808,767	$ 44,070,536
General and Administrative Expense [Member] | Refinancing Fee [Member]
Related Party Transaction [Line Items]
Percentage of refinancing amount	0.50%
Related party transaction, expenses from transactions with related party	$ 86,675	$ 3,283,737	$ 0

Related Party Arrangements - 87

Related Party Arrangements - Narrative - Restricted Stock Agreement (Details) - Advisor [Member] - Advisor [Member] - USD ($)	Jun. 11, 2014	Dec. 31, 2016	Dec. 31, 2015
Restricted Stock [Member] | Tranche One [Member]
Related Party Transaction [Line Items]
Shares of restricted stock vesting percentage	50.00%
Restricted Stock [Member] | Tranche Two [Member]
Related Party Transaction [Line Items]
Shares of restricted stock vesting percentage	50.00%
Restricted Stock Agreement [Member]
Related Party Transaction [Line Items]
Issuance of restricted common stock to advisor (in shares)	488,281.25
Issuance of restricted common stock to Advisor	$ 5,000,000
Restricted Stock Agreement [Member] | Restricted Stock [Member]
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 10.24
Restricted Stock Agreement [Member] | Restricted Stock [Member] | Tranche One [Member]
Related Party Transaction [Line Items]
Shares of restricted stock vesting percentage			50.00%
Restricted Stock Agreement [Member] | Restricted Stock [Member] | Tranche Two [Member]
Related Party Transaction [Line Items]
Shares of restricted stock vesting percentage		50.00%

Related Party Arrangements - 88

Related Party Arrangements - Narrative - Contributions, Settlement and Release Agreements (Details) - Texas Water Code [Member] - Company Subsidiaries and Property Manager [Member]	12 Months Ended
	Dec. 31, 2017USD ($)lawsuit
Related Party Transaction [Line Items]
Number of Class Action Lawsuits | lawsuit	2
Litigation settlement amount	$ 378,405
Loss contingency accrual	$ 350,851

Incentive Award Plan and Inde89

Incentive Award Plan and Independent Director Compensation - Narrative (Details)	Aug. 08, 2017shares	Aug. 09, 2016shares	Aug. 11, 2015directorshares	Aug. 10, 2015shares	Dec. 31, 2017USD ($)shares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of board of directors members | director			2
Share-based compensation | $					$ 85,486	$ 76,285	$ 184,350
Private Offering [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from issuance of common stock | $					$ 2,000,000
Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted shares (in shares)					0	0
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted shares (in shares)					7,500	7,500	14,000
Restricted Stock [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock vesting percentage					25.00%
Restricted Stock [Member] | Director [Member] | Re-Election [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted shares (in shares)	2,500	2,500	2,500		2,500
Restricted Stock [Member] | Independent Directors Compensation Plan [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted common stock, award vesting period					3 years
Restricted Stock [Member] | Independent Directors Compensation Plan [Member] | Director [Member] | Initial Election [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted shares (in shares)					5,000
Restricted Stock [Member] | Incentive Award Plan [Member] | Director [Member] | Larry H. Dale [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted shares (in shares)				2,000
Restricted Stock [Member] | Incentive Award Plan [Member] | Director [Member] | Kerry D. Vandell [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted shares (in shares)				2,000
Restricted Stock [Member] | Incentive Award Plan [Member] | Director [Member] | Don B. Saulic [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted shares (in shares)			5,000

Derivative Financial Instrume90

Derivative Financial Instruments - Schedule of Interest Rate Derivative Instruments (Details) - Interest Rate Cap [Member] - Cash Flow Hedging [Member] - Not Designated as Hedging Instrument [Member]	Dec. 31, 2017USD ($)instrument	Dec. 31, 2016USD ($)instrument
Derivative [Line Items]
Number of instruments | instrument	18	43
Notional Amount	$ 458,655,000	$ 973,400,000
Weighted Average Rate Cap	2.89%	2.70%
Fair Value	$ 51,646	$ 618,841
LIBOR [Member]
Derivative [Line Items]
Variable Rate	1.56%	0.77%

Derivative Financial Instrume91

Derivative Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Unrealized gain (loss) on derivatives		$ (604,545)	$ 61,698	$ (2,032,746)
Interest Rate Cap [Member]
Derivative [Line Items]
Unrealized gain (loss) on derivatives		(604,545)	61,698	(2,032,746)
Payments for (Proceeds from) Derivative Instrument, Investing Activities	$ 37,350		259,000
Interest Rate Cap [Member] | Deferred Financing Costs and Other Assets, Net [Member]
Derivative [Line Items]
Fair value of interest rate cap agreements	$ 51,646	51,646	618,841
Interest Rate Cap [Member] | Interest Expense [Member]
Derivative [Line Items]
Unrealized gain (loss) on derivatives		$ (604,545)	$ 61,698	$ (2,032,746)

Selected Quarterly Results (u92

Selected Quarterly Results (unaudited) - Schedule of Unaudited Quarterly Financial Information (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 47,978,462	$ 55,592,107	$ 55,118,406	$ 54,280,265	$ 54,936,076	$ 56,371,925	$ 54,022,623	$ 52,906,908	$ 212,969,240	$ 218,237,532	$ 209,390,658
Net income (loss)	$ 86,101,893	$ (2,326,578)	$ (5,656,573)	$ (5,644,875)	$ (4,223,102)	$ (9,699,187)	$ (8,039,220)	$ (3,618,142)	$ 72,473,867	$ (25,579,651)	$ (13,024,358)
Loss per common share - basic and diluted (in dollars per share)	$ 1.14	$ (0.03)	$ (0.07)	$ (0.07)	$ (0.05)	$ (0.13)	$ (0.11)	$ (0.05)	$ 0.96	$ (0.34)	$ (0.18)
Distributions declared per common share (in dollars per share)	$ 0.181	$ 0.181	$ 0.179	$ 0.177	$ 0.180	$ 0.180	$ 0.178	$ 0.178	$ 0.718	$ 0.716

Subsequent Events - Narrative -

Subsequent Events - Narrative - Distributions Paid (Details) - USD ($)	Mar. 01, 2018	Feb. 01, 2018	Jan. 02, 2018
Dividend Paid [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Distributions paid, common stock, including distribution reinvestment plan	$ 4,140,790	$ 4,594,989	$ 4,595,301

Subsequent Events - Narrative94

Subsequent Events - Narrative - Redemption (Details) - Share Repurchase Plan [Member] - Common Stock [Member] - USD ($)	Jan. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Subsequent Event [Line Items]
Redemption of common stock (in shares)		730,953	479,147
Stock repurchase plan, stock redeemed, value		$ 8,000,000	$ 5,000,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Redemption of common stock (in shares)	181,404
Stock repurchase plan, stock redeemed, value	$ 2,000,000
Redemption price per share (in dollars per share)	$ 11.03

Subsequent Events - Narrative95

Subsequent Events - Narrative - Estimated Value per Share (Details)	Mar. 13, 2018$ / shares
Subsequent Event [Member]
Subsequent Event [Line Items]
Estimated value per share (in dollars per share)	$ 10.84

Subsequent Events - Narrative96

Subsequent Events - Narrative - Sales (Details) - Discontinued Operations, Disposed of by Sale [Member] - Subsequent Event [Member]	Feb. 28, 2018USD ($)apartment	Jan. 31, 2018USD ($)apartment	Jan. 05, 2018USD ($)apartment
The Moorings Property [Member]
Subsequent Event [Line Items]
Number of units in real estate property (in number of units or apartments) | apartment			216
Consideration | $			$ 28,100,000
Arrowhead Property [Member]
Subsequent Event [Line Items]
Number of units in real estate property (in number of units or apartments) | apartment		200
Consideration | $		$ 23,600,000
Willow Crossing [Member]
Subsequent Event [Line Items]
Number of units in real estate property (in number of units or apartments) | apartment	579
Consideration | $	$ 79,000,000

Subsequent Events - Narrative97

Subsequent Events - Narrative - Distributions Declared (Details) - $ / shares	Mar. 20, 2018	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2016	Mar. 13, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Common share, distribution rate per share per day, declared (in dollars per share)		$ 0.001958		$ 0.001964
Subsequent Event [Member]
Subsequent Event [Line Items]
Share price (in dollars per share)					$ 10.84
Common Stock [Member]
Subsequent Event [Line Items]
Common share, distribution rate per share per day, declared (in dollars per share)			$ 0.001964
Common stock, distribution rate, percentage			7.00%
Share price (in dollars per share)						$ 10.24
Common Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Common share, distribution rate per share per day, declared (in dollars per share)	$ 0.001683
Common stock, distribution rate, percentage	6.00%
Share price (in dollars per share)	$ 10.24

Subsequent Events - Narrative98

Subsequent Events - Narrative - Tender Offer (Details) - USD ($)	Mar. 20, 2018	Mar. 13, 2018	Dec. 31, 2017
Subsequent Event [Member]
Subsequent Event [Line Items]
Share price (in dollars per share)		$ 10.84
Common Stock [Member]
Subsequent Event [Line Items]
Share price (in dollars per share)			$ 10.24
Common Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Share price (in dollars per share)	$ 10.24
Tender Offer [Member] | Common Stock [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Tender offer amount	$ 100,000,000
Share price (in dollars per share)	$ 9

- Real Estate Assets and Accumu

- Real Estate Assets and Accumulated Depreciation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Real Estate and Accumulated Depreciation [Line Items]
Encumbrances				$ 875,785,938
Initial Cost of Company
Land				130,589,065
Buildings and Improvements				1,074,284,655
Total				1,204,873,720
Cost Capitalized Subsequent to Acquisition				68,298,797
Gross Amount at which Carried at Close of Period
Land				130,640,065
Buildings and Improvements				1,117,656,919
Total	$ 1,694,278,958	$ 1,666,901,082	$ 1,636,953,413	1,248,296,985
Accumulated Depreciation and Amortization				$ (221,581,654)
Real Estate [Roll Forward]
Balance at the beginning of the year	1,694,278,958	1,666,901,082	1,636,953,413
Improvements	15,621,609	28,485,659	30,484,330
Cost of real estate sold	(461,332,750)	0	0
Write-off of disposed and fully depreciated and fully amortized assets	(270,832)	(1,107,783)	(536,661)
Balance at the end of the year	1,248,296,985	1,694,278,958	1,666,901,082
Accumulated Depreciation [Roll Forward]
Balance at the beginning of the year	232,744,083	163,445,987	98,342,452
Depreciation and amortization expense	67,755,152	69,513,484	65,640,196
Write-off of accumulated depreciation and amortization of real estate assets sold	(78,793,834)	0	0
Write-off of disposed and fully depreciated and fully amortized assets	(123,747)	(215,388)	(536,661)
Balance at the end of the year	221,581,654	$ 232,744,083	$ 163,445,987
Park Place Condominiums [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 7,971,245
Initial Cost of Company
Land				1,470,991
Buildings and Improvements				9,744,009
Total				11,215,000
Cost Capitalized Subsequent to Acquisition				891,623
Gross Amount at which Carried at Close of Period
Land				1,470,991
Buildings and Improvements				10,353,712
Total	11,824,704			11,824,704
Accumulated Depreciation and Amortization				$ (2,761,466)
Real Estate [Roll Forward]
Balance at the end of the year	11,824,704
Clarion Park Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 5,350,567
Initial Cost of Company
Land				842,987
Buildings and Improvements				8,257,013
Total				9,100,000
Cost Capitalized Subsequent to Acquisition				1,106,718
Gross Amount at which Carried at Close of Period
Land				842,987
Buildings and Improvements				9,123,102
Total	9,966,089			9,966,089
Accumulated Depreciation and Amortization				$ (2,502,288)
Real Estate [Roll Forward]
Balance at the end of the year	9,966,089
Cooper Creek [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 5,060,029
Initial Cost of Company
Land				460,362
Buildings and Improvements				8,114,638
Total				8,575,000
Cost Capitalized Subsequent to Acquisition				739,956
Gross Amount at which Carried at Close of Period
Land				460,362
Buildings and Improvements				8,512,276
Total	8,972,638			8,972,638
Accumulated Depreciation and Amortization				$ (2,141,890)
Real Estate [Roll Forward]
Balance at the end of the year	8,972,638
Truman Farm Villas [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 8,357,513
Initial Cost of Company
Land				838,685
Buildings and Improvements				11,661,315
Total				12,500,000
Cost Capitalized Subsequent to Acquisition				1,160,711
Gross Amount at which Carried at Close of Period
Land				838,685
Buildings and Improvements				12,579,622
Total	13,418,307			13,418,307
Accumulated Depreciation and Amortization				$ (3,086,741)
Real Estate [Roll Forward]
Balance at the end of the year	13,418,307
EBT Lofts [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 17,069,537
Initial Cost of Company
Land				2,346,503
Buildings and Improvements				17,602,343
Total				19,948,846
Cost Capitalized Subsequent to Acquisition				950,341
Gross Amount at which Carried at Close of Period
Land				2,346,503
Buildings and Improvements				18,147,292
Total	20,493,795			20,493,795
Accumulated Depreciation and Amortization				$ (4,438,904)
Real Estate [Roll Forward]
Balance at the end of the year	20,493,795
Windsor on the River [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 22,255,805
Initial Cost of Company
Land				3,325,556
Buildings and Improvements				32,424,444
Total				35,750,000
Cost Capitalized Subsequent to Acquisition				1,570,987
Gross Amount at which Carried at Close of Period
Land				3,325,556
Buildings and Improvements				32,809,836
Total	36,135,392			36,135,392
Accumulated Depreciation and Amortization				$ (7,443,135)
Real Estate [Roll Forward]
Balance at the end of the year	36,135,392
Renaissance St. Andrews [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 20,920,589
Initial Cost of Company
Land				2,737,794
Buildings and Improvements				29,462,206
Total				32,200,000
Cost Capitalized Subsequent to Acquisition				890,318
Gross Amount at which Carried at Close of Period
Land				2,737,794
Buildings and Improvements				29,802,911
Total	32,540,705			32,540,705
Accumulated Depreciation and Amortization				$ (6,806,899)
Real Estate [Roll Forward]
Balance at the end of the year	32,540,705
Spring Creek of Edmond [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 20,500,000
Initial Cost of Company
Land				2,544,634
Buildings and Improvements				27,240,628
Total				29,785,262
Cost Capitalized Subsequent to Acquisition				801,624
Gross Amount at which Carried at Close of Period
Land				2,544,634
Buildings and Improvements				27,520,688
Total	30,065,322			30,065,322
Accumulated Depreciation and Amortization				$ (6,134,374)
Real Estate [Roll Forward]
Balance at the end of the year	30,065,322
Montclair Parc Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 9,421,511
Initial Cost of Company
Land				724,771
Buildings and Improvements				14,375,229
Total				15,100,000
Cost Capitalized Subsequent to Acquisition				559,050
Gross Amount at which Carried at Close of Period
Land				724,771
Buildings and Improvements				14,673,690
Total	15,398,461			15,398,461
Accumulated Depreciation and Amortization				$ (3,078,593)
Real Estate [Roll Forward]
Balance at the end of the year	15,398,461
Sonoma Grande Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 12,668,570
Initial Cost of Company
Land				1,413,437
Buildings and Improvements				18,484,692
Total				19,898,129
Cost Capitalized Subsequent to Acquisition				883,287
Gross Amount at which Carried at Close of Period
Land				1,413,437
Buildings and Improvements				18,962,658
Total	20,376,095			20,376,095
Accumulated Depreciation and Amortization				$ (4,024,722)
Real Estate [Roll Forward]
Balance at the end of the year	20,376,095
Estancia Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 17,821,492
Initial Cost of Company
Land				1,321,194
Buildings and Improvements				21,852,963
Total				23,174,157
Cost Capitalized Subsequent to Acquisition				373,442
Gross Amount at which Carried at Close of Period
Land				1,321,194
Buildings and Improvements				21,780,821
Total	23,102,015			23,102,015
Accumulated Depreciation and Amortization				$ (4,387,251)
Real Estate [Roll Forward]
Balance at the end of the year	23,102,015
Montelena Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 15,375,368
Initial Cost of Company
Land				1,536,795
Buildings and Improvements				22,639,028
Total				24,175,823
Cost Capitalized Subsequent to Acquisition				450,787
Gross Amount at which Carried at Close of Period
Land				1,536,795
Buildings and Improvements				22,641,163
Total	24,177,958			24,177,958
Accumulated Depreciation and Amortization				$ (4,640,794)
Real Estate [Roll Forward]
Balance at the end of the year	24,177,958
Valley Farms Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 14,200,991
Initial Cost of Company
Land				1,917,909
Buildings and Improvements				20,027,929
Total				21,945,838
Cost Capitalized Subsequent to Acquisition				304,306
Gross Amount at which Carried at Close of Period
Land				1,917,909
Buildings and Improvements				19,900,357
Total	21,818,266			21,818,266
Accumulated Depreciation and Amortization				$ (4,070,502)
Real Estate [Roll Forward]
Balance at the end of the year	21,818,266
Hilliard Park Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 0
Initial Cost of Company
Land				92,255
Buildings and Improvements				1,282,745
Total				1,375,000
Cost Capitalized Subsequent to Acquisition				398,992
Gross Amount at which Carried at Close of Period
Land				92,255
Buildings and Improvements				1,655,073
Total	1,747,328			1,747,328
Accumulated Depreciation and Amortization				$ (396,701)
Real Estate [Roll Forward]
Balance at the end of the year	1,747,328
Sycamore Terrace Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 11,527,640
Initial Cost of Company
Land				2,094,728
Buildings and Improvements				14,655,272
Total				16,750,000
Cost Capitalized Subsequent to Acquisition				649,415
Gross Amount at which Carried at Close of Period
Land				2,094,728
Buildings and Improvements				14,902,088
Total	16,996,816			16,996,816
Accumulated Depreciation and Amortization				$ (3,025,710)
Real Estate [Roll Forward]
Balance at the end of the year	16,996,816
Hilliard Summit Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 13,934,462
Initial Cost of Company
Land				2,250,208
Buildings and Improvements				17,999,792
Total				20,250,000
Cost Capitalized Subsequent to Acquisition				1,800,800
Gross Amount at which Carried at Close of Period
Land				2,250,208
Buildings and Improvements				19,379,126
Total	21,629,334			21,629,334
Accumulated Depreciation and Amortization				$ (4,011,976)
Real Estate [Roll Forward]
Balance at the end of the year	21,629,334
Springmarc Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 36,312,924
Initial Cost of Company
Land				3,055,614
Buildings and Improvements				49,444,386
Total				52,500,000
Cost Capitalized Subsequent to Acquisition				1,170,324
Gross Amount at which Carried at Close of Period
Land				3,055,614
Buildings and Improvements				49,852,825
Total	52,908,439			52,908,439
Accumulated Depreciation and Amortization				$ (10,081,619)
Real Estate [Roll Forward]
Balance at the end of the year	52,908,439
Renaissance at St. Andrews Condominiums [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 5,723,070
Initial Cost of Company
Land				1,052,401
Buildings and Improvements				7,347,599
Total				8,400,000
Cost Capitalized Subsequent to Acquisition				563,464
Gross Amount at which Carried at Close of Period
Land				1,052,401
Buildings and Improvements				7,731,204
Total	8,783,605			8,783,605
Accumulated Depreciation and Amortization				$ (1,633,180)
Real Estate [Roll Forward]
Balance at the end of the year	8,783,605
Ashley Oaks Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 20,647,194
Initial Cost of Company
Land				2,595,387
Buildings and Improvements				27,404,613
Total				30,000,000
Cost Capitalized Subsequent to Acquisition				754,674
Gross Amount at which Carried at Close of Period
Land				2,595,387
Buildings and Improvements				27,617,253
Total	30,212,640			30,212,640
Accumulated Depreciation and Amortization				$ (5,746,961)
Real Estate [Roll Forward]
Balance at the end of the year	30,212,640
Arrowhead Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 9,469,959
Initial Cost of Company
Land				2,212,402
Buildings and Improvements				3,062,598
Total				5,275,000
Cost Capitalized Subsequent to Acquisition				9,476,836
Gross Amount at which Carried at Close of Period
Land				2,212,402
Buildings and Improvements				12,473,398
Total	14,685,800			14,685,800
Accumulated Depreciation and Amortization				$ (1,420,780)
Real Estate [Roll Forward]
Balance at the end of the year	14,685,800
The Moorings Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 13,116,770
Initial Cost of Company
Land				3,081,522
Buildings and Improvements				15,918,478
Total				19,000,000
Cost Capitalized Subsequent to Acquisition				2,500,159
Gross Amount at which Carried at Close of Period
Land				3,081,522
Buildings and Improvements				17,984,441
Total	21,065,963			21,065,963
Accumulated Depreciation and Amortization				$ (4,143,855)
Real Estate [Roll Forward]
Balance at the end of the year	21,065,963
Forty-57 Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 28,758,708
Initial Cost of Company
Land				2,657,734
Buildings and Improvements				38,012,528
Total				40,670,262
Cost Capitalized Subsequent to Acquisition				532,915
Gross Amount at which Carried at Close of Period
Land				2,657,734
Buildings and Improvements				37,728,776
Total	40,386,510			40,386,510
Accumulated Depreciation and Amortization				$ (7,317,754)
Real Estate [Roll Forward]
Balance at the end of the year	40,386,510
Keystone Farms Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 23,441,688
Initial Cost of Company
Land				3,008,363
Buildings and Improvements				31,700,639
Total				34,709,002
Cost Capitalized Subsequent to Acquisition				313,479
Gross Amount at which Carried at Close of Period
Land				3,008,363
Buildings and Improvements				31,388,326
Total	34,396,689			34,396,689
Accumulated Depreciation and Amortization				$ (6,104,552)
Real Estate [Roll Forward]
Balance at the end of the year	34,396,689
Riverford Crossing Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 8,345,925
Initial Cost of Company
Land				1,669,405
Buildings and Improvements				11,080,595
Total				12,750,000
Cost Capitalized Subsequent to Acquisition				416,653
Gross Amount at which Carried at Close of Period
Land				1,669,405
Buildings and Improvements				11,291,281
Total	12,960,686			12,960,686
Accumulated Depreciation and Amortization				$ (2,257,472)
Real Estate [Roll Forward]
Balance at the end of the year	12,960,686
Southpointe at Valley Farms North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 24,260,315
Initial Cost of Company
Land				2,529,318
Buildings and Improvements				37,266,648
Total				39,795,966
Cost Capitalized Subsequent to Acquisition				5,865,351
Gross Amount at which Carried at Close of Period
Land				2,580,318
Buildings and Improvements				42,405,923
Total	44,986,241			44,986,241
Accumulated Depreciation and Amortization				$ (10,042,782)
Real Estate [Roll Forward]
Balance at the end of the year	44,986,241
Montecito Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 16,480,903
Initial Cost of Company
Land				1,700,810
Buildings and Improvements				24,025,543
Total				25,726,353
Cost Capitalized Subsequent to Acquisition				409,298
Gross Amount at which Carried at Close of Period
Land				1,700,810
Buildings and Improvements				23,946,198
Total	25,647,008			25,647,008
Accumulated Depreciation and Amortization				$ (4,562,139)
Real Estate [Roll Forward]
Balance at the end of the year	25,647,008
Hilliard Grand Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 11,798,975
Initial Cost of Company
Land				2,389,613
Buildings and Improvements				16,128,107
Total				18,517,720
Cost Capitalized Subsequent to Acquisition				706,515
Gross Amount at which Carried at Close of Period
Land				2,389,613
Buildings and Improvements				16,449,002
Total	18,838,615			18,838,615
Accumulated Depreciation and Amortization				$ (3,064,098)
Real Estate [Roll Forward]
Balance at the end of the year	18,838,615
The Hills at Fair Oaks [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 5,843,116
Initial Cost of Company
Land				1,424,432
Buildings and Improvements				7,560,527
Total				8,984,959
Cost Capitalized Subsequent to Acquisition				724,810
Gross Amount at which Carried at Close of Period
Land				1,424,432
Buildings and Improvements				8,061,147
Total	9,485,579			9,485,579
Accumulated Depreciation and Amortization				$ (1,677,861)
Real Estate [Roll Forward]
Balance at the end of the year	9,485,579
Library Lofts East [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 15,520,062
Initial Cost of Company
Land				2,625,024
Buildings and Improvements				20,849,131
Total				23,474,155
Cost Capitalized Subsequent to Acquisition				3,041,815
Gross Amount at which Carried at Close of Period
Land				2,625,024
Buildings and Improvements				23,325,780
Total	25,950,804			25,950,804
Accumulated Depreciation and Amortization				$ (4,722,731)
Real Estate [Roll Forward]
Balance at the end of the year	25,950,804
The Trails at Buda Ranch [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 43,655,146
Initial Cost of Company
Land				3,277,884
Buildings and Improvements				47,118,797
Total				50,396,681
Cost Capitalized Subsequent to Acquisition				284,310
Gross Amount at which Carried at Close of Period
Land				3,277,884
Buildings and Improvements				46,764,643
Total	50,042,527			50,042,527
Accumulated Depreciation and Amortization				$ (8,522,634)
Real Estate [Roll Forward]
Balance at the end of the year	50,042,527
Deep Deuce at Bricktown [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 14,800,655
Initial Cost of Company
Land				3,135,425
Buildings and Improvements				21,753,469
Total				24,888,894
Cost Capitalized Subsequent to Acquisition				2,076,142
Gross Amount at which Carried at Close of Period
Land				3,135,425
Buildings and Improvements				23,227,150
Total	26,362,575			26,362,575
Accumulated Depreciation and Amortization				$ (4,647,489)
Real Estate [Roll Forward]
Balance at the end of the year	26,362,575
Deer Valley Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 16,008,257
Initial Cost of Company
Land				1,585,035
Buildings and Improvements				15,264,965
Total				16,850,000
Cost Capitalized Subsequent to Acquisition				168,175
Gross Amount at which Carried at Close of Period
Land				1,585,035
Buildings and Improvements				15,148,381
Total	16,733,416			16,733,416
Accumulated Depreciation and Amortization				$ (2,729,119)
Real Estate [Roll Forward]
Balance at the end of the year	16,733,416
Grayson Ridge [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 17,103,335
Initial Cost of Company
Land				1,596,212
Buildings and Improvements				18,503,788
Total				20,100,000
Cost Capitalized Subsequent to Acquisition				764,467
Gross Amount at which Carried at Close of Period
Land				1,596,212
Buildings and Improvements				18,817,435
Total	20,413,647			20,413,647
Accumulated Depreciation and Amortization				$ (3,505,866)
Real Estate [Roll Forward]
Balance at the end of the year	20,413,647
Rosemont at Olmos Park [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 12,052,239
Initial Cost of Company
Land				1,605,839
Buildings and Improvements				14,694,161
Total				16,300,000
Cost Capitalized Subsequent to Acquisition				344,373
Gross Amount at which Carried at Close of Period
Land				1,605,839
Buildings and Improvements				14,710,619
Total	16,316,458			16,316,458
Accumulated Depreciation and Amortization				$ (2,727,552)
Real Estate [Roll Forward]
Balance at the end of the year	16,316,458
Retreat at Quail North [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 38,272,259
Initial Cost of Company
Land				9,869,925
Buildings and Improvements				27,130,075
Total				37,000,000
Cost Capitalized Subsequent to Acquisition				2,913,086
Gross Amount at which Carried at Close of Period
Land				9,869,925
Buildings and Improvements				28,681,430
Total	38,551,355			38,551,355
Accumulated Depreciation and Amortization				$ (6,182,589)
Real Estate [Roll Forward]
Balance at the end of the year	38,551,355
The Lodge at Trails Edge [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 27,184,269
Initial Cost of Company
Land				5,858,663
Buildings and Improvements				31,741,337
Total				37,600,000
Cost Capitalized Subsequent to Acquisition				1,620,389
Gross Amount at which Carried at Close of Period
Land				5,858,663
Buildings and Improvements				32,641,310
Total	38,499,973			38,499,973
Accumulated Depreciation and Amortization				$ (6,120,866)
Real Estate [Roll Forward]
Balance at the end of the year	38,499,973
Arbors At Carrollton [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 35,325,595
Initial Cost of Company
Land				6,512,468
Buildings and Improvements				33,637,532
Total				40,150,000
Cost Capitalized Subsequent to Acquisition				1,993,354
Gross Amount at which Carried at Close of Period
Land				6,512,468
Buildings and Improvements				34,842,064
Total	41,354,532			41,354,532
Accumulated Depreciation and Amortization				$ (6,600,161)
Real Estate [Roll Forward]
Balance at the end of the year	41,354,532
Waterford on the Meadow [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 17,285,905
Initial Cost of Company
Land				3,184,857
Buildings and Improvements				20,215,143
Total				23,400,000
Cost Capitalized Subsequent to Acquisition				959,492
Gross Amount at which Carried at Close of Period
Land				3,184,857
Buildings and Improvements				20,674,645
Total	23,859,502			23,859,502
Accumulated Depreciation and Amortization				$ (3,948,393)
Real Estate [Roll Forward]
Balance at the end of the year	23,859,502
The Belmont [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 27,323,636
Initial Cost of Company
Land				5,450,417
Buildings and Improvements				27,449,583
Total				32,900,000
Cost Capitalized Subsequent to Acquisition				1,683,415
Gross Amount at which Carried at Close of Period
Land				5,450,417
Buildings and Improvements				28,438,837
Total	33,889,254			33,889,254
Accumulated Depreciation and Amortization				$ (5,227,739)
Real Estate [Roll Forward]
Balance at the end of the year	33,889,254
Meritage at Steiner Ranch [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 24,920,866
Initial Cost of Company
Land				3,760,329
Buildings and Improvements				29,239,671
Total				33,000,000
Cost Capitalized Subsequent to Acquisition				1,252,728
Gross Amount at which Carried at Close of Period
Land				3,760,329
Buildings and Improvements				29,876,504
Total	33,636,833			33,636,833
Accumulated Depreciation and Amortization				$ (5,470,712)
Real Estate [Roll Forward]
Balance at the end of the year	33,636,833
Tapestry Park Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 20,256,062
Initial Cost of Company
Land				3,241,747
Buildings and Improvements				21,908,253
Total				25,150,000
Cost Capitalized Subsequent to Acquisition				1,025,576
Gross Amount at which Carried at Close of Period
Land				3,241,747
Buildings and Improvements				22,409,484
Total	25,651,231			25,651,231
Accumulated Depreciation and Amortization				$ (4,209,680)
Real Estate [Roll Forward]
Balance at the end of the year	25,651,231
Dawntree Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 57,665,058
Initial Cost of Company
Land				8,091,870
Buildings and Improvements				49,908,130
Total				58,000,000
Cost Capitalized Subsequent to Acquisition				8,010,749
Gross Amount at which Carried at Close of Period
Land				8,091,870
Buildings and Improvements				56,203,972
Total	64,295,842			64,295,842
Accumulated Depreciation and Amortization				$ (10,993,070)
Real Estate [Roll Forward]
Balance at the end of the year	64,295,842
Stuart Hall Lofts [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 0
Initial Cost of Company
Land				4,402,862
Buildings and Improvements				30,419,853
Total				34,822,715
Cost Capitalized Subsequent to Acquisition				566,428
Gross Amount at which Carried at Close of Period
Land				4,402,862
Buildings and Improvements				30,512,561
Total	34,915,423			34,915,423
Accumulated Depreciation and Amortization				$ (5,114,124)
Real Estate [Roll Forward]
Balance at the end of the year	34,915,423
BriceGrove Park Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 17,038,807
Initial Cost of Company
Land				3,776,547
Buildings and Improvements				22,762,411
Total				26,538,958
Cost Capitalized Subsequent to Acquisition				409,431
Gross Amount at which Carried at Close of Period
Land				3,776,547
Buildings and Improvements				22,625,701
Total	26,402,248			26,402,248
Accumulated Depreciation and Amortization				$ (3,956,992)
Real Estate [Roll Forward]
Balance at the end of the year	26,402,248
Retreat at Hamburg Place [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 33,534,900
Initial Cost of Company
Land				2,383,256
Buildings and Improvements				37,416,744
Total				39,800,000
Cost Capitalized Subsequent to Acquisition				1,460,565
Gross Amount at which Carried at Close of Period
Land				2,383,256
Buildings and Improvements				38,206,736
Total	40,589,992			40,589,992
Accumulated Depreciation and Amortization				$ (6,171,368)
Real Estate [Roll Forward]
Balance at the end of the year	40,589,992
Cantare - Indian Lake Village [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 14,217,203
Initial Cost of Company
Land				1,344,233
Buildings and Improvements				17,530,767
Total				18,875,000
Cost Capitalized Subsequent to Acquisition				392,193
Gross Amount at which Carried at Close of Period
Land				1,344,233
Buildings and Improvements				17,570,936
Total	18,915,169			18,915,169
Accumulated Depreciation and Amortization				$ (2,811,132)
Real Estate [Roll Forward]
Balance at the end of the year	18,915,169
Landing at Mansfield [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 19,265,284
Initial Cost of Company
Land				3,585,171
Buildings and Improvements				19,739,829
Total				23,325,000
Cost Capitalized Subsequent to Acquisition				2,026,881
Gross Amount at which Carried at Close of Period
Land				3,585,171
Buildings and Improvements				21,158,111
Total	24,743,282			24,743,282
Accumulated Depreciation and Amortization				$ (3,672,956)
Real Estate [Roll Forward]
Balance at the end of the year	24,743,282
The Heights Apartments [Member]
Real Estate and Accumulated Depreciation [Line Items]
Ownership Percent				100.00%
Encumbrances				$ 17,721,534
Initial Cost of Company
Land				2,005,491
Buildings and Improvements				22,224,509
Total				24,230,000
Cost Capitalized Subsequent to Acquisition				338,393
Gross Amount at which Carried at Close of Period
Land				2,005,491
Buildings and Improvements				22,146,431
Total	24,151,922			24,151,922
Accumulated Depreciation and Amortization				$ (3,241,482)
Real Estate [Roll Forward]
Balance at the end of the year	$ 24,151,922

- Real Estate Assets and Acc100

- Real Estate Assets and Accumulated Depreciation (Footnote) (Details)	Dec. 31, 2017USD ($)
SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract]
Unamortized portion of loan premiums (discounts) on assumed debt	$ 700,000
Deferred financing costs, net	5,109,819
Aggregate cost of real estate for federal income tax purposes	$ 1,290,000,000