National Storage Affiliates Trust (NSA) 10-Q 4 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 03, 2016
Entity [Abstract]
Entity Registrant Name	National Storage Affiliates Trust
Entity Central Index Key	1,618,563
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		37,477,628

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Real estate
Self storage properties	$ 1,619,014	$ 1,147,201
Less accumulated depreciation	(97,993)	(68,100)
Self storage properties, net	1,521,021	1,079,101
Cash and cash equivalents	11,474	6,665
Restricted cash	4,627	2,712
Debt issuance costs, net	2,911	1,923
Other assets, net	23,371	8,648
Assets held for sale	18,702	0
Total assets	1,582,106	1,099,049
Liabilities
Debt financing	722,622	567,795
Accounts payable and accrued liabilities	29,593	9,694
Deferred revenue	7,844	5,513
Total liabilities	760,059	583,002
Commitments and contingencies (Note 10)
Equity
Common shares of beneficial interest, par value $0.01 per share. 250,000,000 shares authorized, 35,915,871 and 23,015,751 shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively	359	230
Additional paid-in capital	450,986	236,392
Retained (deficit) earnings	(8,013)	11
Accumulated other comprehensive loss	(184)	0
Total shareholders' equity	443,148	236,633
Noncontrolling interests	378,899	279,414
Total equity	822,047	516,047
Total liabilities and equity	$ 1,582,106	$ 1,099,049

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Common shares of beneficial interest, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares of beneficial interest, authorized (in shares)	250,000,000	250,000,000
Common shares of beneficial interest, issued (in shares)	35,915,871	23,015,751
Common shares of beneficial interest, outstanding (in shares)	35,915,871	23,015,751

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
REVENUE
Rental revenue	$ 51,263	$ 34,600	$ 135,548	$ 92,650
Other property-related revenue	1,686	1,078	4,334	2,969
Total revenue	52,949	35,678	139,882	95,619
OPERATING EXPENSES
Property operating expenses	17,330	12,000	46,064	32,668
General and administrative expenses	5,259	4,056	14,431	11,856
Depreciation and amortization	14,319	10,341	38,299	30,192
Total operating expenses	36,908	26,397	98,794	74,716
Income from operations	16,041	9,281	41,088	20,903
OTHER INCOME (EXPENSE)
Interest expense	(6,265)	(4,246)	(17,050)	(16,052)
Loss on early extinguishment of debt	0	0	(136)	(914)
Acquisition costs	(1,737)	(2,874)	(4,733)	(4,192)
Organizational and offering expenses	0	0	0	(58)
Non-operating expense	(95)	(52)	(378)	(256)
Other income (expense)	(8,097)	(7,172)	(22,297)	(21,472)
Net income (loss)	7,944	2,109	18,791	(569)
Net (income) loss attributable to noncontrolling interests	(7,955)	2,263	(9,222)	8,405
Net (loss) income attributable to National Storage Affiliates Trust	$ (11)	$ 4,372	$ 9,569	$ 7,836
Earnings (loss) per share - basic (in dollars per share)	$ 0	$ 0.19	$ 0.35	$ 0.61
Earnings (loss) per share - diluted (in dollars per share)	$ 0	$ 0.03	$ 0.25	$ 0.06
Weighted average shares outstanding - basic (in shares)	35,080	23,000	27,084	12,924
Weighted average shares outstanding - diluted (in shares)	35,080	63,456	75,492	38,758
Dividends declared per common share (in dollars per share)	$ 0.22	$ 0.19	$ 0.64	$ 0.34

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 7,944	$ 2,109	$ 18,791	$ (569)
Other comprehensive income (loss)
Unrealized gain (loss) on derivative contracts	243	(1,258)	(8,194)	(2,528)
Reclassification of other comprehensive loss to interest expense	920	407	1,829	1,182
Other comprehensive income (loss)	1,163	(851)	(6,365)	(1,346)
Comprehensive income (loss)	9,107	1,258	12,426	(1,915)
Comprehensive (income) loss attributable to noncontrolling interests	(8,469)	3,114	(2,901)	9,751
Comprehensive income attributable to National Storage Affiliates Trust	$ 638	$ 4,372	$ 9,525	$ 7,836

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - 9 months ended Sep. 30, 2016 - USD ($) $ in Thousands	Total	OP Units and Subordinated Performance Units [Member]	LTIP units [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Retained (Deficit) Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]	Noncontrolling Interests [Member]OP Units and Subordinated Performance Units [Member]	Noncontrolling Interests [Member]LTIP units [Member]
Balances (in shares) at Dec. 31, 2015	23,015,751			23,015,751
Balances at Dec. 31, 2015	$ 516,047			$ 230	$ 236,392	$ 11	$ 0	$ 279,414
Increase (Decrease) in Stockholders' Equity [Roll Forward]
OP equity recorded in business combination		$ 104,173	$ 597						$ 104,173	$ 597
Redemptions of OP units (in shares)				845,780
Redemptions of OP units	0			$ 8	9,488		(17)	(9,479)
Issuance of common shares (in shares)			180,304	12,046,250
Issuance of common shares, net of offering costs	237,519			$ 121	237,398			0
Effect of changes in ownership for consolidated entities	0				(32,383)		(123)	32,506
Equity-based compensation expense	1,913				91			1,822
Issuance of LTIP units for acquisition expenses	56							56
Issuance of restricted common shares (in shares)				8,090
Issuance of restricted common shares, value	0
Reduction in receivables from partners of OP	958							958
Other comprehensive loss	(6,365)						(44)	(6,321)
Common share dividends	(17,593)					(17,593)	0
Distributions to limited partners of OP	(34,049)							(34,049)
Net income (loss)	$ 18,791					9,569	0	9,222
Balances (in shares) at Sep. 30, 2016	35,915,871			35,915,871
Balances at Sep. 30, 2016	$ 822,047			$ 359	$ 450,986	$ (8,013)	$ (184)	$ 378,899

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 18,791	$ (569)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	38,299	30,192
Amortization of debt issuance costs	1,493	2,121
Amortization of debt discount and premium, net	(1,557)	(1,260)
Loss on debt extinguishment	136	414
Unrealized loss on fair value of derivatives	0	68
LTIP units issued for acquisition expenses	56	1,020
Equity-based compensation expense	1,913	2,375
Change in assets and liabilities, net of effects of business combinations:
Restricted cash	(1,377)	(864)
Other assets	(681)	(714)
Accounts payable and accrued liabilities	9,993	4,861
Deferred revenue	(133)	(88)
Net Cash Provided by Operating Activities	66,933	37,556
CASH FLOWS FROM INVESTING ACTIVITIES
Acquisition of self storage properties	(323,822)	(132,196)
Capital expenditures	(8,478)	(2,985)
Investments in and advances to unconsolidated joint venture	(4,873)	0
Deposits and advances for self storage property and other acquisitions	(5,415)	(3,258)
Expenditures for corporate furniture, equipment and other	(472)	(291)
Change in restricted cash designated for capital expenditures	(40)	219
Net Cash Used In Investing Activities	(343,100)	(138,511)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of common shares	238,712	278,070
Borrowings under debt financings	498,500	173,943
Receipts for OP unit subscriptions	799	1,011
Collection of receivables from issuance of OP equity	570	774
Principal payments under debt financings	(401,204)	(324,247)
Payment of dividends to common shareholders	(17,593)	(3,453)
Distributions to noncontrolling interests	(33,392)	(20,112)
Change in restricted cash for financing activity	0	(167)
Debt issuance costs	(4,904)	(1,717)
Equity offering costs	(512)	(5,370)
Net Cash Provided by Financing Activities	280,976	98,732
Increase (Decrease) in Cash and Cash Equivalents	4,809	(2,223)
CASH AND CASH EQUIVALENTS
Beginning of period	6,665	9,009
End of period	11,474	6,786
Supplemental Cash Flow Information
Cash paid for interest	16,501	15,719
Consideration exchanged in business combinations:
Issuance of OP units and subordinated performance units	104,298	42,113
Deposits on acquisitions applied to purchase price	631	745
LTIP units vesting upon acquisition of properties	597	0
Assumption of mortgages payable	61,628	49,855
Note payable to related party to settle assumed mortgages	0	5,342
Other net liabilities assumed	2,692	870
Notes receivable settled upon acquisition of properties	0	1,778
Fair value of noncontrolling interests in acquired subsidiaries	0	15,097
Increase in OP unit subscription liability through reduced distributions	267	293
Settlement of acquisition receivables through reduced distributions	390	1,137
Increase (decrease) in payables for deferred offering costs	806	(1,342)
Settlement of offering costs from equity issuance proceeds	$ 11,248	$ 20,930

ORGANIZATION AND NATURE OF OPER

ORGANIZATION AND NATURE OF OPERATIONS	9 Months Ended
	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND NATURE OF OPERATIONS	ORGANIZATION AND NATURE OF OPERATIONS National Storage Affiliates Trust was organized in the state of Maryland on May 16, 2013 and is a fully integrated, self-administered and self-managed real estate investment trust focused on the self storage sector. As used herein, "NSA," the "Company," "we," "our," and "us" refers to National Storage Affiliates Trust and its consolidated subsidiaries, except where the context indicates otherwise. The Company has elected and qualified as a real estate investment trust ("REIT") for U.S. federal income tax purposes commencing with its taxable year ending December 31, 2015. Through its controlling interest as the sole general partner of NSA OP, LP (its "operating partnership"), a Delaware limited partnership formed on February 13, 2013, the Company is focused on the ownership, operation, and acquisition of self storage properties in the United States. Pursuant to the Agreement of Limited Partnership (as amended, the "LP Agreement") of its operating partnership, the Company's operating partnership is authorized to issue Class A Units ("OP units"), different series of Class B Units ("subordinated performance units"), and Long-Term Incentive Plan Units ("LTIP units"). The Company also owns certain of its self storage properties through other consolidated limited partnership subsidiaries of its operating partnership, which we refer to as "DownREIT partnerships." The DownREIT partnerships issue equity ownership interests that are intended to be economically equivalent to the Company's OP units ("DownREIT OP units") and subordinated performance units ("DownREIT subordinated performance units"). The Company completed its initial public offering on April 28, 2015, pursuant to which it sold 23,000,000 of the Company's common shares of beneficial interest, $0.01 par value per share ("common shares"), at a price of $13.00 per share, which included 3,000,000 common shares sold upon the exercise in full by the underwriters of their option to purchase additional shares. These transactions resulted in net proceeds to the Company of approximately $278.1 million , after deducting the underwriting discount and before additional expenses associated with the offering. On July 6, 2016, the Company closed a follow-on public offering of 12,046,250 of its common shares, which included 1,571,250 common shares sold upon the exercise in full by the underwriters of their option to purchase additional common shares, at a public offering price of $20.75 per share. The Company received aggregate net proceeds from the offering of approximately $237.5 million after deducting the underwriting discount and additional expenses associated with the offering. The Company owned 352 self storage properties in 19 states with approximately 21.0 million rentable square feet in approximately 168,000 storage units as of September 30, 2016 . These properties are managed with local operational focus and expertise by the Company's participating regional operators ("PROs"). These PROs are SecurCare Self Storage, Inc. and its controlled affiliates ("SecurCare"), Kevin Howard Real Estate Inc., d/b/a Northwest Self Storage and its controlled affiliates ("Northwest"), Optivest Properties LLC and its controlled affiliates ("Optivest"), Guardian Storage Centers LLC and its controlled affiliates ("Guardian"), Move It Self Storage and its controlled affiliates ("Move It"), Arizona Mini Storage Management Company d/b/a Storage Solutions and its controlled affiliates ("Storage Solutions"), and Hide-Away Storage Services, Inc. and its controlled affiliates ("Hide-Away").

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying condensed consolidated financial statements are presented on the accrual basis of accounting in accordance with U.S. generally accepted accounting principles ("GAAP") and have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC") regarding interim financial reporting. Accordingly, certain information and footnote disclosures required by GAAP for complete financial statements have been condensed or omitted in accordance with such rules and regulations. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation of the consolidated financial statements have been included. Principles of Consolidation The Company's financial statements include the accounts of its operating partnership and its controlled subsidiaries. All significant intercompany balances and transactions have been eliminated in the consolidation of entities. When the Company obtains an economic interest in an entity, the Company evaluates the entity to determine if the entity is deemed a variable interest entity ("VIE"), and if the Company is deemed to be the primary beneficiary, in accordance with authoritative guidance issued on the consolidation of VIEs. When an entity is not deemed to be a VIE, the Company considers the provisions of additional guidance to determine whether the general partner controls a limited partnership or similar entity when the limited partners have certain rights. The Company consolidates all entities that are VIEs and of which the Company is deemed to be the primary beneficiary. During the nine months ended September 30, 2016 , the Company adopted Accounting Standards Update ("ASU") 2015-02 and concluded that although its operating partnership and all DownREIT partnerships now meet the criteria as a VIE, no change was required to the Company's accounting for any of its interests in less than wholly owned DownREIT partnerships or its operating partnership. The sole significant asset of National Storage Affiliates Trust is its investment in its operating partnership, and consequently, substantially all of the Company’s assets and liabilities represent those assets and liabilities of its operating partnership. Accordingly, there has been no change to the recognized amounts in the Company's consolidated balance sheets and statements of operations or amounts reported in the Company's consolidated statements of cash flows. As of September 30, 2016 , the Company's operating partnership was the primary beneficiary of, and therefore consolidated, 21 DownREIT partnerships that are considered VIEs, which owned 34 self storage properties. The net book value of the real estate owned by these VIEs was $258.0 million and $262.6 million as of September 30, 2016 and December 31, 2015 , respectively. For the DownREIT partnerships which are subject to fixed rate mortgages payable, the carrying value of such fixed rate mortgages payable held by these VIEs was $41.9 million and $43.2 million as of September 30, 2016 and December 31, 2015 , respectively. The creditors of the consolidated VIEs do not have recourse to the Company's general credit. Noncontrolling Interests All of the limited partner equity interests in the operating partnership not held by the Company are reflected as noncontrolling interests. Noncontrolling interests also include ownership interests in DownREIT partnerships held by entities other than the operating partnership or its subsidiaries. In the consolidated statements of operations, the Company allocates net income (loss) attributable to noncontrolling interests to arrive at net income (loss) attributable to National Storage Affiliates Trust. For transactions that result in changes to the Company's ownership interest in its operating partnership, the carrying amount of noncontrolling interests is adjusted to reflect such changes. The difference between the fair value of the consideration received or paid and the amount by which the noncontrolling interest is adjusted is reflected as an adjustment to additional paid-in capital on the consolidated balance sheets. Allocation of Net Income (Loss) The distribution rights and priorities set forth in the operating partnership's LP Agreement differ from what is reflected by the underlying percentage ownership interests of the unitholders. Accordingly, the Company allocates GAAP income (loss) utilizing the hypothetical liquidation at book value ("HLBV") method, in which the Company allocates income or loss based on the change in each unitholders’ claim on the net assets of its operating partnership at period end after adjusting for any distributions or contributions made during such period. The HLBV method is commonly applied to equity investments where cash distribution percentages vary at different points in time and are not directly linked to an equity holder’s ownership percentage. The HLBV method is a balance sheet-focused approach to income (loss) allocation. A calculation is prepared at each balance sheet date to determine the amount that unitholders would receive if the operating partnership were to liquidate all of its assets (at GAAP net book value) and distribute the resulting proceeds to its creditors and unitholders based on the contractually defined liquidation priorities. The difference between the calculated liquidation distribution amounts at the beginning and the end of the reporting period, after adjusting for capital contributions and distributions, is used to derive each unitholder's share of the income (loss) for the period. Due to the stated liquidation priorities and because the HLBV method incorporates non-cash items such as depreciation expense, in any given period, income or loss may be allocated disproportionately to unitholders as compared to their respective ownership percentage in the operating partnership, and net income (loss) attributable to National Storage Affiliates Trust could be more or less net income than actual cash distributions received and more or less income or loss than what may be received in the event of an actual liquidation. Additionally, the HLBV method could result in net income (or net loss) attributable to National Storage Affiliates Trust during a period when the Company reports consolidated net loss (or net income), or net income (or net loss) attributable to National Storage Affiliates Trust in excess of the Company's consolidated net income (or net loss). The computations of basic and diluted earnings (loss) per share may be materially affected by these disproportionate income (loss) allocations, resulting in volatile fluctuations of basic and diluted earnings (loss) per share. Readers of this Form 10-Q and investors are cautioned not to place undue reliance on the Company's income (loss) allocations or earnings (loss) per share without considering the effects described above, including the effect that depreciation and amortization have on income (loss), net book value and the application of the HLBV method. Other Comprehensive Income (Loss) The Company has cash flow hedge derivative instruments that are measured at fair value with unrealized gains or losses recognized in other comprehensive income (loss) with a corresponding adjustment to accumulated other comprehensive loss within equity, as discussed further in Note 11 . Under the HLBV method of allocating income (loss) discussed above, a calculation is prepared at each balance sheet date by applying the HLBV method including, and excluding, the assets and liabilities resulting from the Company's cash flow hedge derivative instruments to determine comprehensive income (loss) attributable to National Storage Affiliates Trust. As a result of the distribution rights and priorities set forth in the operating partnership's LP Agreement, in any given period, other comprehensive income (loss) may be allocated disproportionately to unitholders as compared to their respective ownership percentage in the operating partnership and as compared to their respective allocation of net income (loss). Assets held for sale The Company classifies properties as held for sale when certain criteria are met. At such time, the properties, including significant assets and liabilities that are expected to be transferred as part of a sale transaction, are presented separately on the consolidated balance sheet at the lower of carrying value or estimated fair value less costs to sell and depreciation is no longer recognized. As of September 30, 2016 , the Company had three self storage properties classified as held for sale. These properties were part of a larger portfolio of properties acquired during the third quarter of 2016 whereby the Company decided during the underwriting process to pursue the sale of certain properties following the acquisition. As of December 31, 2015 the Company had no self storage properties classified as held for sale. The results of operations for the self storage properties classified as held for sale are reflected within income from operations in the Company's consolidated statements of operations. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 will replace most existing revenue recognition guidance in GAAP when it becomes effective. ASU 2014-09 is effective for the Company on January 1, 2018, with early application permitted for the Company on January 1, 2017. ASU 2014-09 permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting. In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis, which modifies the current consolidation guidance. Under this guidance, limited partnerships may no longer be viewed as VIEs if the limited partners hold certain rights over the general partner. Alternatively, limited partnerships not previously viewed as VIEs may now be considered VIEs in the absence of such rights. The Company adopted ASU 2015-02 during the nine months ended September 30, 2016 , as more fully described above, see " –Principles of Consolidation". In April 2015, the FASB issued ASU 2015-03, Interest—Imputation of Interest, which requires the presentation of debt issuance costs as a direct deduction from the carrying amount of the related debt liabilities. In August 2015, the FASB issued ASU 2015-15 that permits debt issuance costs related to line-of-credit arrangements to be presented as an asset and amortized over the term of the line-of-credit arrangement regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The Company adopted ASUs 2015-03 and 2015-15 as of January 1, 2016. The adoption resulted in the reclassification of certain debt issuance costs from assets to a reduction in the carrying amount of the Company's debt financings applied retrospectively to all periods. These reclassifications totaled $5.4 million and $2.8 million as of September 30, 2016 and December 31, 2015, respectively. Debt issuance costs related to the Company's revolving credit facility (the "Revolver") remain classified within "Debt issuance costs, net" in the Company's consolidated balance sheets. In February 2016, the FASB issued ASU 2016-02, Leases, which amends the existing guidance for accounting for leases, including requiring lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases and operating leases and lessees to recognize most leases on-balance sheet as lease liabilities with corresponding right-of-use assets. ASU 2016-02 is effective for the Company on January 1, 2019, with early application permitted. ASU 2016-02 requires a modified retrospective approach, with entities applying the new guidance at the beginning of the earliest period presented in the financial statements in which they first apply the new standard, with certain elective transition relief. The Company is evaluating the effect that ASU 2016-02 will have on its operating leases, consolidated financial statements and related disclosures. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows, which clarifies the classification of certain cash receipts and cash payments in the statement of cash flows, including debt prepayment or extinguishment costs, settlement of contingent consideration arising from a business combination, insurance settlement proceeds, and distributions from certain equity method investees. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. Early adoption is permitted. The Company is evaluating the effect that ASU 2016-15 will have on its consolidated financial statements and related disclosures.

NONCONTROLLING INTERESTS

NONCONTROLLING INTERESTS	9 Months Ended
	Sep. 30, 2016
Noncontrolling Interest [Abstract]
NONCONTROLLING INTERESTS	NONCONTROLLING INTERESTS As of September 30, 2016 and December 31, 2015 , units reflecting noncontrolling interests consisted of the following: September 30, December 31, 2016 2015 OP units 25,503,628 21,556,006 Subordinated performance units 11,011,649 9,302,989 LTIP units 1,552,905 2,784,761 DownREIT units DownREIT OP units 1,834,786 1,834,786 DownREIT subordinated performance units 4,386,999 4,386,999 Total 44,289,967 39,865,541 While the Company controls its operating partnership and manages the daily operations of its operating partnership's business, the Company did not have an ownership interest or share in its operating partnership's profits and losses prior to the completion of the Company's initial public offering. The increase in OP Units outstanding from December 31, 2015 to September 30, 2016 was due to 3,499,542 OP units issued in connection with the acquisition of self storage properties and LTIP units converted into OP units, as discussed further below, partially offset by the redemption of 845,780 OP units. The increase in subordinated performance units outstanding from December 31, 2015 to September 30, 2016 was related to the acquisition of self storage properties. The decrease in LTIP units outstanding from December 31, 2015 to September 30, 2016 was due to the conversion of 1,293,860 LTIP units into 1,293,860 OP units and the forfeiture of 118,300 LTIP units, partially offset by the issuance of 180,304 compensatory LTIP units to employees, consultants and trustees.

SELF STORAGE PROPERTIES

SELF STORAGE PROPERTIES	9 Months Ended
	Sep. 30, 2016
Real Estate [Abstract]
SELF STORAGE PROPERTIES	SELF STORAGE PROPERTIES Self storage properties are summarized as follows (dollars in thousands): September 30, December 31, 2016 2015 Land $ 419,219 $ 315,867 Buildings and improvements 1,196,142 829,093 Furniture and equipment 3,653 2,241 Total self storage properties 1,619,014 1,147,201 Less accumulated depreciation (97,993 ) (68,100 ) Self storage properties, net $ 1,521,021 $ 1,079,101 Depreciation expense related to self storage properties amounted to $11.1 million and $7.4 million during the three months ended September 30, 2016 and 2015 , respectively, and $29.9 million and $20.3 million during the nine months ended September 30, 2016 and 2015 , respectively.

SELF STORAGE PROPERTY ACQUISITI

SELF STORAGE PROPERTY ACQUISITIONS	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
SELF STORAGE PROPERTY ACQUISITIONS	SELF STORAGE PROPERTY ACQUISITIONS The Company acquired 76 self storage properties with an estimated fair value of $493.7 million during the nine months ended September 30, 2016 . Of these acquisitions, 21 self storage properties with an estimated fair value of $157.6 million were acquired by the Company from its PROs. These self storage property acquisitions were accounted for as business combinations whereby the Company recognized the estimated fair value of the acquired assets and assumed liabilities on the respective dates of such acquisitions. The Company preliminarily allocated the total purchase price to the estimated fair value of tangible and intangible assets acquired, and liabilities assumed. The Company allocated a portion of the purchase price to identifiable intangible assets consisting of customer in-place leases which were recorded at estimated fair value of $12.4 million , resulting in a total fair value of $481.3 million allocated to real estate. The following table summarizes the consideration for the business combinations completed by the Company during the nine months ended September 30, 2016 (dollars in thousands): Acquisitions Closed During the Three Months Ended: Number of Properties Summary of Consideration Value of OP Equity (1) Liabilities Assumed (Assets Acquired) Total Fair Value Cash Mortgages (2) Other March 31, 2016 17 $ 63,300 $ 19,068 $ 5,861 $ 584 $ 88,813 June 30, 2016 25 61,263 80,986 55,767 1,212 199,228 September 30, 2016 34 199,890 4,841 — 896 205,627 Total 76 $ 324,453 $ 104,895 $ 61,628 $ 2,692 $ 493,668 (1) Value of OP equity represents the fair value of OP units, subordinated performance units and LTIP units. (2) $12.2 million of the mortgages assumed in connection with self storage property acquisitions were subsequently repaid during the nine months ended September 30, 2016 . The results of operations for these business combinations are included in the Company's statements of operations beginning on the respective closing date for each acquisition. For the three and nine months ended September 30, 2016 , the accompanying statements of operations includes aggregate total revenue of $11.2 million and $19.4 million , respectively, and operating income of $1.3 million and $2.2 million , respectively, related to the 76 self storage properties acquired. Acquisition costs in the accompanying statements of operations include consulting fees, transaction expenses, and other costs related to business combinations, which amounted to $1.7 million and $4.7 million for the three and nine months ended September 30, 2016 , respectively. Pro Forma Financial Information The pro forma financial information set forth below reflects incremental adjustments to the historical data of the Company to give effect to the acquisitions and related financing activities for (i) the two self storage properties discussed in Note 12 that were acquired subsequent to September 30, 2016 , as if each acquisition had occurred on January 1, 2015, (ii) 32 of the 34 self storage properties acquired during the three months ended September 30, 2016 , as if the acquisitions had occurred on January 1, 2015 (pro forma financial information is not presented for two of the self storage properties acquired during the three months ended September 30, 2016 since the information required is not available to the Company), (iii) the 25 self storage properties acquired during the three months ended June 30, 2016, as if the acquisitions had occurred on January 1, 2015, (iv) 15 of the 17 self storage properties acquired during the three months ended March 31, 2016, as if the acquisitions had occurred on January 1, 2015 (pro forma financial information is not presented for two of the self storage properties acquired during the three months ended March 31, 2016 since the information required is not available to the Company), (v) one of the 15 self storage properties acquired during the three months ended September 30, 2015, as if the acquisitions had occurred on January 1, 2014 (pro forma financial information is not presented for 14 of the self storage properties acquired during the three months ended September 30, 2015 since the information required is not available to the Company), (vi) the 21 self storage properties that were acquired during the three months ended June 30, 2015, as if each acquisition had occurred on January 1, 2014, and (vii) the six self storage properties that were acquired during the three months ended March 31, 2015, as if each had occurred on January 1, 2014. As described in greater detail above, given that certain information with respect to the self storage properties the Company acquired is not available to the Company, readers of this Form 10-Q and investors are cautioned not to place undue reliance on the Company's pro forma financial information. The pro forma information presented below does not purport to represent what the actual results of operations would have been for the periods indicated, nor does it purport to represent the Company's future results of operations. The following table summarizes on a pro forma basis the results of operations for the three and nine months ended September 30, 2016 and 2015 (dollars in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Pro forma total revenue: Historical results 52,949 35,678 139,882 95,619 Acquisitions subsequent to September 30, 2016 419 382 1,206 976 Acquisitions during the three months ended September 30, 2016 (1) 1,664 4,393 11,317 13,177 Acquisitions during the three months ended June 30, 2016 — 5,053 5,894 14,791 Acquisitions during the three months ended March 31, 2016 (2) — 1,865 842 5,455 Acquisitions during the three months ended September 30, 2015 (3) — 109 — 537 Acquisitions during the three months ended June 30, 2015 — — — 3,782 Acquisitions during the three months ended March 31, 2015 — — — 86 Total $ 55,032 $ 47,480 $ 159,141 $ 134,423 Pro forma net income (loss): (4) Historical results 7,944 2,109 18,791 (569 ) Acquisitions subsequent to September 30, 2016 77 (98 ) 153 (440 ) Acquisitions during the three months ended September 30, 2016 (1) 759 (1,214 ) 1,781 (3,608 ) Acquisitions during the three months ended June 30, 2016 1,268 (610 ) 5,758 (2,177 ) Three Months Ended Nine Months Ended 2016 2015 2016 2015 Acquisitions during the three months ended March 31, 2016 (2) 478 (70 ) 2,548 (2,162 ) Acquisitions during the three months ended September 30, 2015 (3) 34 53 169 3,047 Acquisitions during the three months ended June 30, 2015 — 472 1,055 2,764 Acquisitions during the three months ended March 31, 2015 — 317 53 1,525 Total $ 10,560 $ 959 $ 30,308 $ (1,620 ) (1) Reflects 32 of the 34 self storage properties acquired during this period because the information required with respect to the two remaining acquisitions during this period is not available to the Company. (2) Reflects 15 of the 17 self storage properties acquired during this period because the information required with respect to the two remaining acquisitions during this period is not available to the Company. (3) Reflects one of the 15 self storage properties acquired during this period because the information required with respect to the 14 remaining acquisitions during this period is not available to the Company. (4) Significant assumptions and adjustments in preparation of the pro forma information include the following: (i) for the cash portion of the purchase price, the Company assumed borrowings under the Company's revolving line of credit with interest computed based on the effective interest rate of 1.93% as of September 30, 2016 ; (ii) for assumed debt financing directly associated with the acquisition of specific self storage properties, interest was computed for the entirety of the periods presented using the effective interest rates under such financings; and (iii) for acquisition costs of $4.7 million incurred during the nine months ended September 30, 2016 , pro forma adjustments give effect to these costs as if they were incurred on January 1, 2015.

OTHER ASSETS

OTHER ASSETS	9 Months Ended
	Sep. 30, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
OTHER ASSETS	OTHER ASSETS Other assets consist of the following (dollars in thousands): September 30, December 31, 2016 2015 Customer in-place leases, net of accumulated amortization of $6,268 and $4,312, respectively $ 7,832 $ 4,209 Receivables: Trade, net 1,562 1,093 PROs and other affiliates 438 232 Investments in and advances to unconsolidated joint venture 5,123 — Property acquisition and other deposits 5,547 763 Interest rate derivative assets — 331 Prepaid expenses and other 2,047 1,486 Corporate furniture, equipment and other, net 822 534 Total $ 23,371 $ 8,648

DEBT FINANCING

DEBT FINANCING	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
DEBT FINANCING	DEBT FINANCING The Company's outstanding debt as of September 30, 2016 and December 31, 2015 is summarized as follows (dollars in thousands): Interest September 30, December 31, Rate (1) 2016 2015 Credit Facility: Revolving line of credit 1.93% $ 85,500 $ 187,975 Term loan A 2.61% 225,000 200,000 Term loan B 3.15% 100,000 — Term loan facility 3.08% 100,000 — Fixed rate mortgages payable 4.05% 206,087 176,911 Total principal 716,587 564,886 Unamortized debt issuance costs and debt premium, net 6,035 2,909 Total debt $ 722,622 $ 567,795 (1) Represents the effective interest rate as of September 30, 2016 . Effective interest rate incorporates the stated rate plus the impact of interest rate cash flow hedges and discount and premium amortization, if applicable. For the revolving line of credit, the effective interest rate excludes fees for unused borrowings. Credit Facility On May 6, 2016, the Company entered into an amended and restated agreement with a syndicated group of lenders with respect to its unsecured credit facility (the "credit facility"), which was originally entered into on April 1, 2014. The amendment increased the borrowing capacity of the credit facility by $125.0 million for a total credit facility of $675.0 million , consisting of three components: (i) a Revolver which provides for a total borrowing commitment up to $350.0 million , whereby the Company may borrow, repay and re-borrow amounts under the revolving line of credit, (ii) a $225.0 million tranche A term loan facility (the "Term Loan A"), and (iii) a $100.0 million tranche B term loan facility (the "Term Loan B" and together with the Revolver and the Term Loan A, the "Facilities"). The Revolver matures in May 2020; provided that the Company may elect to extend the maturity to May 2021 by paying an extension fee of 0.15% of the total borrowing commitment thereunder at the time of extension and meeting other customary conditions with respect to compliance. The Term Loan A matures in May 2021 and the Term Loan B matures in May 2022. None of the Facilities is subject to any scheduled reduction or amortization payments prior to maturity. Interest rates applicable to loans under the Facilities are determined based on a 1, 2, 3 or 6 month LIBOR period (as elected by the Company at the beginning of any applicable interest period) plus an applicable margin or a base rate, determined by the greatest of the Key Bank prime rate, the federal funds rate plus 0.50% or one month LIBOR plus 1.00% , plus an applicable margin. The applicable margins for the Facilities are leverage based and range from 1.35% to 2.15% for LIBOR loans and 0.35% to 1.15% for base rate loans; provided that after such time as the Company achieves an investment grade rating from at least two rating agencies, the Company may elect (but is not required to elect) that the Facilities are subject to the rating based on applicable margins ranging from 0.85% to 2.30% for LIBOR Loans and 0.00% to 1.30% for base rate loans. The Company is also required to pay the following usage based fees ranging from 0.15% to 0.25% with respect to the unused portion of the Revolver; provided that if the Company makes an investment grade pricing election as described in the preceding sentence, the Company will be required to pay rating based fees ranging from 0.125% to 0.300% with respect to the entire Revolver in lieu of any usage based fees. As of September 30, 2016 , the Company would have had the capacity to borrow the full remaining Revolver commitments of $264.5 million while remaining in compliance with the Facilities' financial covenants described in the following paragraph. The Company is required to comply with the following financial covenants under the Facilities: • Maximum total leverage ratio not to exceed 60% • Minimum fixed charge coverage ratio of at least 1.5 x • Minimum net worth of at least $682.6 million plus 75% of future equity issuances • Maximum unsecured debt to unencumbered asset value ratio not to exceed 60% • Unencumbered adjusted net operating income to unsecured interest expense of at least 2.0 x In addition, the terms of the Facilities contain customary affirmative and negative covenants that, among other things, limit the Company's ability to make distributions or certain investments, incur debt, incur liens and enter into certain transactions. At September 30, 2016 , the Company was in compliance with all such covenants. Term Loan Facility On June 30, 2016, the Company entered into a credit agreement with a syndicated group of lenders to make available a term loan facility (the "Term Loan Facility") in an aggregate amount of $100.0 million . The Term Loan Facility matures in June 2023. The entire outstanding principal amount of, and all accrued but unpaid interest, is due on the maturity date. The Company has an expansion option under the Term Loan Facility, which, if exercised in full, would provide for a total Term Loan Facility in an aggregate amount of $200.0 million . Interest rates applicable to loans under the Term Loan Facility are payable during such periods as such loans are LIBOR loans, at the applicable LIBOR based on a 1, 2, 3 or 6 month LIBOR period (as elected by the Company at the beginning of any applicable interest period) plus an applicable margin, and during the period that such loans are base rate loans, at the base rate under the Term Loan Facility in effect from time to time plus an applicable margin. The base rate under the Term Loan Facility is equal to the greatest of the Capital One prime rate, the federal funds rate plus 0.50% or one month LIBOR plus 1.00% . The applicable margin for the Term Loan Facility is leverage-based and ranges from 1.75% to 2.35% for LIBOR loans and 0.75% to 1.35% for base rate loans; provided that after such time as the Company achieves an investment grade rating from at least two rating agencies, the Company may elect (but is not required to elect) that the Term Loan Facility is subject to the rating based on applicable margins ranging from 1.50% to 2.45% for LIBOR Loans and 0.50% to 1.45% for base rate loans. The Company is required to comply with the same financial covenants under the Term Loan Facility as it is with the Facilities. In addition, the terms of the Term Loan Facility contain customary affirmative and negative covenants that, among other things, limit the Company's ability to make distributions or certain investments, incur debt, incur liens and enter into certain transactions. Fixed Rate Mortgages Payable Fixed rate mortgages have scheduled maturities at various dates through October 2031, and have effective interest rates that range from 2.44% to 5.00% . Principal and interest are generally payable monthly or in monthly interest-only payments with balloon payments due at maturity. Future Debt Obligations Based on existing debt agreements in effect as of September 30, 2016 , the scheduled principal and maturity payments for outstanding borrowings under the Company's credit facility and fixed rate mortgages are presented in the table below (in thousands): Year Ending December 31, Scheduled Principal and Maturity Payments Premium Amortization and Unamortized Debt Issuance Costs Total Remainder of 2016 $ 2,001 $ 249 $ 2,250 2017 17,495 611 18,106 2018 10,617 514 11,131 2019 4,983 446 5,429 2020 124,745 94 124,839 2021 232,509 (5 ) 232,504 Thereafter 324,237 4,126 328,363 $ 716,587 $ 6,035 $ 722,622

EARNINGS PER SHARE

EARNINGS PER SHARE	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE The following table sets forth the computation of basic and diluted earnings (loss) per common share for the three and nine months ended September 30, 2016 and 2015 , respectively (in thousands, except per share amounts): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Earnings (loss) per common share - basic and diluted Numerator Net income (loss) $ 7,944 $ 2,109 $ 18,791 $ (569 ) Net (income) loss attributable to noncontrolling interests (7,955 ) 2,263 (9,222 ) 8,405 Net (loss) income attributable to National Storage Affiliates Trust (11 ) 4,372 9,569 7,836 Distributed and undistributed earnings allocated to participating securities (4 ) (3 ) (13 ) (6 ) Net (loss) income attributable to common shareholders - basic (15 ) 4,369 9,556 7,830 Effect of assumed conversion of dilutive securities — (2,275 ) 9,135 (5,646 ) Net (loss) income attributable to common shareholders - diluted $ (15 ) $ 2,094 $ 18,691 $ 2,184 Denominator Weighted average shares outstanding - basic 35,080 23,000 27,084 12,924 Effect of dilutive securities: Weighted average OP units outstanding — 21,109 23,761 13,773 Weighted average DownREIT OP unit equivalents outstanding — 1,432 1,835 949 Weighted average LTIP units outstanding — 1,844 2,162 1,030 Weighted average subordinated performance units and DownREIT subordinated performance unit equivalents — 16,071 20,650 10,082 Weighted average shares outstanding - diluted 35,080 63,456 75,492 38,758 Earnings (loss) per share - basic $ — $ 0.19 $ 0.35 $ 0.61 Earnings (loss) per share - diluted $ — $ 0.03 $ 0.25 $ 0.06 As discussed in Note 2 , the Company allocates GAAP income (loss) utilizing the HLBV method, in which the Company allocates income or loss based on the change in each unitholders' claim on the net assets of its operating partnership at period end after adjusting for any distributions or contributions made during such period. Due to the stated liquidation priorities and because the HLBV method incorporates non-cash items such as depreciation expense, in any given period, income or loss may be allocated disproportionately to National Storage Affiliates Trust and noncontrolling interests, resulting in volatile fluctuations of basic and diluted earnings (loss) per share. Additionally, the Company did not have an ownership interest or share in its operating partnership's profits and losses prior to the completion of the Company's initial public offering. As a result, all of the operating partnership's profits and losses for the period from January 1, 2015 to April 28, 2015 were allocated to noncontrolling interests. Outstanding equity interests of the operating partnership and DownREIT partnerships are considered potential common shares for purposes of calculating diluted earnings (loss) per share as the unitholders may, through the exercise of redemption rights, obtain common shares, subject to various restrictions. Basic earnings per share is calculated based on the weighted average number of common shares outstanding during the period. Diluted earnings per share is calculated by further adjusting for the dilutive impact using the treasury stock method for unvested LTIP units subject to a service condition outstanding during the period and the if-converted method for any convertible securities outstanding during the period. Generally, following certain lock-out periods, OP units in the operating partnership are redeemable for cash or, at the Company's option, exchangeable for common shares on a one -for-one basis, subject to certain adjustments and DownREIT OP units are redeemable for cash or, at the Company's option, exchangeable for OP units in the operating partnership on a one -for-one basis, subject to certain adjustments in each case. LTIP units may also, under certain circumstances, be convertible into OP units on a one-for-one basis, which are then exchangeable for common shares as described above. Certain LTIP units vested prior to or upon the completion of the Company's initial public offering and certain LTIP units have vested upon the satisfaction of a service condition or will vest upon the satisfaction of a future service condition. Vested LTIP units and unvested LTIP units that vest based on a service condition are allocated income or loss in a similar manner as OP units. Unvested LTIP units subject to a service condition are evaluated for dilution using the treasury stock method. For the three and nine months ended September 30, 2016 , 386,713 unvested LTIP units that vest based on a service condition are excluded from the calculation of diluted earnings (loss) per share as they are not dilutive to earnings (loss) per share. In addition, certain LTIP units vest upon the future acquisition of properties sourced by PROs. For the three and nine months ended September 30, 2016 , 271,400 unvested LTIP units that vest upon the future acquisition of properties are excluded from the calculation of diluted earnings (loss) per share because the contingency for the units to vest has not been attained as of the end of the reported periods. Subordinated performance units may also, under certain circumstances, be convertible into OP units which are exchangeable for common shares as described above, and DownREIT subordinated performance units may, under certain circumstances, be exchangeable for subordinated performance units on a one -for-one basis. Subordinated performance units are only convertible into OP units, after a two year lock-out period and then generally (i) at the holder’s election only upon the achievement of certain performance thresholds relating to the properties to which such subordinated performance units relate or (ii) at the Company's election upon a retirement event of a PRO that holds such subordinated performance units or upon certain qualifying terminations. For the three months ended September 30, 2016, potential common shares totaling 49.8 million related to OP units, DownREIT OP units, subordinated performance units and DownREIT subordinated performance units have been excluded from the calculation of diluted earnings (loss) per share as they are not dilutive to earnings (loss) per share. Although subordinated performance units may only be convertible after a two year lock-out period, the Company assumes a hypothetical conversion of each subordinated performance unit (including each DownREIT subordinated performance unit) into OP units (with subsequently assumed redemption into common shares) for the purposes of calculating diluted weighted average common shares. This hypothetical conversion is calculated using historical financial information, prior to and since the completion of the Company's initial public offering on April 28, 2015, and as a result, is not necessarily indicative of the subsequent results of operations, cash flows or financial position of the Company following the initial public offering or upon expiration of the two -year lock out period on conversions. Participating securities, which consist of unvested restricted common shares, receive dividends equal to those received by common shares. The effect of participating securities for the periods presented above is calculated using the two-class method of allocating distributed and undistributed earnings.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	9 Months Ended
	Sep. 30, 2016
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS Supervisory and Administrative Fees The Company has entered into asset management agreements with the PROs to continue providing leasing, operating, supervisory and administrative services related to the self storage properties contributed by and acquired from the PROs. The asset management agreements generally provide for fees ranging from 5% to 6% of gross revenue for the managed self storage properties. During the three months ended September 30, 2016 and 2015 , the Company incurred $3.0 million and $2.0 million , respectively, for supervisory and administrative fees to the PROs and during the nine months ended September 30, 2016 and 2015 , the Company incurred $7.8 million and $5.4 million , respectively, for supervisory and administrative fees to the PROs. Such fees are included in general and administrative expenses in the accompanying consolidated statements of operations. Affiliate Payroll Services The employees responsible for operation of the self storage properties are employees of the PROs who charge the Company for the costs associated with the respective employees. For the three months ended September 30, 2016 and 2015 , the Company incurred $5.1 million and $3.5 million , respectively, for payroll and related costs reimbursable to these affiliates, and for the nine months ended September 30, 2016 and 2015 , the Company incurred $13.8 million and $9.6 million , respectively, for payroll and related costs reimbursable to these affiliates. Such costs are included in property operating expenses in the accompanying consolidated statements of operations. Due Diligence Costs During the three months ended September 30, 2016 and 2015 , the Company incurred $0.4 million and $0.3 million , respectively, of expenses payable to certain PROs related to self storage property acquisitions sourced by the PROs, and during the nine months ended September 30, 2016 and 2015 , the Company incurred $0.7 million and $0.4 million , respectively, of expenses payable to certain PROs related to self storage property acquisitions sourced by the PROs. These expenses, which are based on the volume of transactions sourced by the PROs, are intended to reimburse the PROs for due diligence costs incurred in the sourcing and underwriting process. These expenses are included in acquisition costs in the accompanying statements of operations.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Proceedings The Company is subject to litigation, claims, and assessments that may arise in the ordinary course of its business activities. Such matters include contractual matters, employment related issues, and regulatory proceedings. Although occasional adverse decisions or settlements may occur, the Company believes that the final disposition of such matters will not have a material adverse effect on the Company's financial position, results of operations, or liquidity.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Recurring Fair Value Measurements The Company sometimes limits its exposure to interest rate fluctuations by entering into interest rate swap agreements. The interest rate swap agreements moderate the Company's exposure to interest rate risk by effectively converting the interest on variable rate debt to a fixed rate. The Company measures its interest rate swap derivatives at fair value on a recurring basis. The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges are recorded in accumulated other comprehensive loss and are subsequently reclassified into earnings in the period that the hedged transaction affects earnings. The ineffective portion of the change in fair value of the derivatives is recognized directly into earnings. Information regarding the Company's interest rate swaps measured at fair value, which are classified within Level 2 of the GAAP fair value hierarchy, is presented below (dollars in thousands): Interest Rate Swaps Designated as Cash Flow Hedges Non-hedge Accounting Interest Rate Swaps Total Fair value at December 31, 2014 $ (865 ) $ (207 ) $ (1,072 ) Unrealized losses included in interest expense — (63 ) (63 ) Designation of interest rate swap as a cash flow hedge (270 ) 270 — Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss 1,182 — 1,182 Unrealized losses included in accumulated other comprehensive loss (2,528 ) — (2,528 ) Fair value at September 30, 2015 $ (2,481 ) $ — $ (2,481 ) Interest Rate Swaps Designated as Cash Flow Hedges Non-hedge Accounting Interest Rate Swaps Total Fair value at December 31, 2015 $ (972 ) $ — $ (972 ) Swap ineffectiveness 11 — 11 Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss 1,829 — 1,829 Unrealized losses included in accumulated other comprehensive loss (8,194 ) — (8,194 ) Fair value at September 30, 2016 $ (7,326 ) $ — $ (7,326 ) As of September 30, 2016 and December 31, 2015 , the Company had outstanding interest rate swaps with aggregate notional amounts of $425.0 million and $199.4 million , respectively, designated as cash flow hedges. As of September 30, 2016 , the Company's swaps had a weighted average remaining term of approximately 4.0 years . The fair value of these swaps are presented within accounts payable and accrued liabilities and other assets in the Company's balance sheets, and the Company recognizes any changes in the fair value as an adjustment of accumulated other comprehensive loss within equity to the extent of their effectiveness. If the forward rates at September 30, 2016 remain constant, the Company estimates that during the next 12 months , the Company would reclassify into earnings approximately $2.8 million of the unrealized losses included in accumulated other comprehensive loss. If market interest rates increase above the 1.34% weighted average fixed rate under these interest rate swaps the Company will benefit from net cash payments due to it from the counterparty to the interest rate swaps. There were no transfers between levels during the nine months ended September 30, 2016 and 2015 . For financial assets and liabilities that utilize Level 2 inputs, the Company utilizes both direct and indirect observable price quotes, including LIBOR yield curves. The Company uses valuation techniques for Level 2 financial assets and liabilities which include LIBOR yield curves at the reporting date as well as assessing counterparty credit risk. Counterparties to these contracts are highly rated financial institutions. Although the Company has determined that the majority of the inputs used to value its derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with the Company's derivatives utilize Level 3 inputs, such as estimates of current credit spreads, to evaluate the likelihood of default by the Company and the counterparties. As of September 30, 2016 , the Company determined that the effect of credit valuation adjustments on the overall valuation of its derivative positions are not significant to the overall valuation of its derivatives. Therefore, the Company has determined that its derivative valuations are appropriately classified in Level 2 of the fair value hierarchy. Fair Value Disclosures The carrying values of cash and cash equivalents, restricted cash, trade receivables, and accounts payable and accrued liabilities reflected in the balance sheets at September 30, 2016 and December 31, 2015 , approximate fair value due to the short term nature of these financial assets and liabilities. The carrying value of variable rate debt financing reflected in the balance sheets at September 30, 2016 and December 31, 2015 approximates fair value as the changes in their associated interest rates reflect the current market and credit risk is similar to when the loans were originally obtained. The fair values of fixed rate mortgages were estimated using the discounted estimated future cash payments to be made on such debt; the discount rates used approximated current market rates for loans, or groups of loans, with similar maturities and credit quality (categorized within Level 2 of the fair value hierarchy). The combined principal balance of the Company's fixed rate mortgages payable was approximately $206.1 million as of September 30, 2016 with a fair value of approximately $227.9 million . In determining the fair value, the Company estimated a weighted average market interest rate of approximately 3.16% , compared to the weighted average contractual interest rate of 5.26% . The combined principal balance of the Company's fixed rate mortgages was approximately $176.9 million as of December 31, 2015 with a fair value of approximately $189.3 million . In determining the fair value as of December 31, 2015 , the Company estimated a weighted average market interest rate of approximately 3.41% , compared to the weighted average contractual interest rate of 5.10% .

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Sep. 30, 2016
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS Self Storage Property Acquisitions From October 1, 2016 through November 1, 2016, the Company acquired two self storage properties for approximately $16.9 million . Consideration for these acquisitions included approximately $10.6 million of cash, OP equity of approximately $6.0 million (consisting of the issuance of 308,345 OP Units) and the assumption of $0.3 million of other working capital liabilities. Of these acquisitions, one was acquired by the Company from a PRO and one was acquired by the Company from a third-party seller. In connection with these acquisitions, the Company incurred less than $0.1 million of expenses, payable to certain PROs, for due diligence costs related to the self storage properties sourced by the PROs. Managed Real Estate Joint Venture On September 9, 2016, the Company, through a newly formed subsidiary (the "NSA Member"), entered into an agreement (the "Agreement") to form a joint venture (the "Joint Venture") with a state pension fund (the "JV Investor," together with the NSA Member, the "Members") advised by Heitman Capital Management LLC to acquire and operate the "iStorage" facilities portfolio (the "JV Portfolio") for an aggregate purchase price of approximately $630 million (the "Acquisition"). The JV Portfolio consists of 66 self-storage facilities containing approximately 4.5 million rentable square feet, configured in over 36,000 storage units and located across 12 states. Separately, the Company, through certain newly formed subsidiaries, also agreed to acquire the property management platform related to the JV Portfolio, including a property management company, a captive insurance company, and related intellectual property for $20 million . On October 4, 2016, the Joint Venture completed its acquisition of the JV Portfolio and the Company completed its acquisition of the iStorage property management platform. The Joint Venture financed the Acquisition with approximately $320 million in equity (approximately $80 million from the NSA Member in exchange for a 25% ownership interest and approximately $240 million from the JV Investor in exchange for a 75% ownership interest) with the balance of the purchase price funded using proceeds from new debt financing. A subsidiary of the Company is acting as the non-member manager of the Joint Venture (the "NSA Manager"). The NSA Manager directs, manages and controls the day-to-day operations and affairs of the Joint Venture but may not cause the Joint Venture to make certain major decisions involving the business of the Joint Venture without the consent of the Members, including the approval of annual budgets, sales and acquisitions of properties, financings, and certain actions relating to bankruptcy. The Joint Venture will pay certain customary fees to the Company for managing and operating the properties, including a monthly property management fee equal to 6% of gross revenues and net sales revenues from Joint Venture assets, an annual call center fee equal to 1% of monthly gross revenues and net sales revenues from Joint Venture assets, a monthly platform fee equal to $1,250 per Joint Venture property, an acquisition fee equal to 0.65% of the gross capitalization (including debt and equity) of the original JV Portfolio, of which one quarter is earned each year over the first four years of the Joint Venture, with an additional fee determined on a sliding scale for future acquisitions, and a development management fee for any development projects acquired by the Joint Venture equal to 3% of construction costs (excluding "soft costs"). An affiliate of the NSA Manager will provide tenant warranty protection to tenants at the Joint Venture properties in exchange for 50% of all proceeds from the tenant warranty protection program at each Joint Venture property. The Company will account for its investment in the Joint Venture using the equity method of accounting. As of September 30, 2016, the Company's investments in and advances to the Joint Venture totaled $5.1 million , and are included within other assets, net in the Company's consolidated balance sheets. Additional disclosures regarding the acquisition of the property management platform, including those related to the preliminary allocation of the purchase price, are not currently available as the Company is in the process of assigning value to the identifiable assets acquired and liabilities assumed. At the Market ("ATM") Program On October 11, 2016, the Company entered into open market sales agreements with four agents, pursuant to which the Company may sell from time to time up to $200 million of the Company's common shares in sales deemed to be "at the market offerings." The Company may offer the common shares through the agents, as sales agents, or to the agents, acting as principals by means of, among others, ordinary brokers’ transactions on the NYSE or otherwise at market prices prevailing at the time of sale or at negotiated prices. During October 2016, the Company sold 1,500,000 of its common shares through the ATM program. The common shares were sold at an average offering price of $19.50 per share, resulting in net proceeds to the Company of approximately $28.9 million after deducting the underwriting discount. The Company used the net proceeds for general corporate purposes, including the repayment of outstanding indebtedness and to fund acquisitions and investments.

SUMMARY OF SIGNIFICANT ACCOUN20

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements are presented on the accrual basis of accounting in accordance with U.S. generally accepted accounting principles ("GAAP") and have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC") regarding interim financial reporting. Accordingly, certain information and footnote disclosures required by GAAP for complete financial statements have been condensed or omitted in accordance with such rules and regulations. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation of the consolidated financial statements have been included.
Principles of Consolidation and Noncontrolling Interest	Principles of Consolidation The Company's financial statements include the accounts of its operating partnership and its controlled subsidiaries. All significant intercompany balances and transactions have been eliminated in the consolidation of entities. Noncontrolling Interests All of the limited partner equity interests in the operating partnership not held by the Company are reflected as noncontrolling interests. Noncontrolling interests also include ownership interests in DownREIT partnerships held by entities other than the operating partnership or its subsidiaries. In the consolidated statements of operations, the Company allocates net income (loss) attributable to noncontrolling interests to arrive at net income (loss) attributable to National Storage Affiliates Trust. For transactions that result in changes to the Company's ownership interest in its operating partnership, the carrying amount of noncontrolling interests is adjusted to reflect such changes. The difference between the fair value of the consideration received or paid and the amount by which the noncontrolling interest is adjusted is reflected as an adjustment to additional paid-in capital on the consolidated balance sheets.
Variable Interest Entity	When the Company obtains an economic interest in an entity, the Company evaluates the entity to determine if the entity is deemed a variable interest entity ("VIE"), and if the Company is deemed to be the primary beneficiary, in accordance with authoritative guidance issued on the consolidation of VIEs. When an entity is not deemed to be a VIE, the Company considers the provisions of additional guidance to determine whether the general partner controls a limited partnership or similar entity when the limited partners have certain rights. The Company consolidates all entities that are VIEs and of which the Company is deemed to be the primary beneficiary. During the nine months ended September 30, 2016 , the Company adopted Accounting Standards Update ("ASU") 2015-02 and concluded that although its operating partnership and all DownREIT partnerships now meet the criteria as a VIE, no change was required to the Company's accounting for any of its interests in less than wholly owned DownREIT partnerships or its operating partnership. The sole significant asset of National Storage Affiliates Trust is its investment in its operating partnership, and consequently, substantially all of the Company’s assets and liabilities represent those assets and liabilities of its operating partnership. Accordingly, there has been no change to the recognized amounts in the Company's consolidated balance sheets and statements of operations or amounts reported in the Company's consolidated statements of cash flows.
Allocation of Net Income (Loss)	Allocation of Net Income (Loss) The distribution rights and priorities set forth in the operating partnership's LP Agreement differ from what is reflected by the underlying percentage ownership interests of the unitholders. Accordingly, the Company allocates GAAP income (loss) utilizing the hypothetical liquidation at book value ("HLBV") method, in which the Company allocates income or loss based on the change in each unitholders’ claim on the net assets of its operating partnership at period end after adjusting for any distributions or contributions made during such period. The HLBV method is commonly applied to equity investments where cash distribution percentages vary at different points in time and are not directly linked to an equity holder’s ownership percentage. The HLBV method is a balance sheet-focused approach to income (loss) allocation. A calculation is prepared at each balance sheet date to determine the amount that unitholders would receive if the operating partnership were to liquidate all of its assets (at GAAP net book value) and distribute the resulting proceeds to its creditors and unitholders based on the contractually defined liquidation priorities. The difference between the calculated liquidation distribution amounts at the beginning and the end of the reporting period, after adjusting for capital contributions and distributions, is used to derive each unitholder's share of the income (loss) for the period. Due to the stated liquidation priorities and because the HLBV method incorporates non-cash items such as depreciation expense, in any given period, income or loss may be allocated disproportionately to unitholders as compared to their respective ownership percentage in the operating partnership, and net income (loss) attributable to National Storage Affiliates Trust could be more or less net income than actual cash distributions received and more or less income or loss than what may be received in the event of an actual liquidation. Additionally, the HLBV method could result in net income (or net loss) attributable to National Storage Affiliates Trust during a period when the Company reports consolidated net loss (or net income), or net income (or net loss) attributable to National Storage Affiliates Trust in excess of the Company's consolidated net income (or net loss). The computations of basic and diluted earnings (loss) per share may be materially affected by these disproportionate income (loss) allocations, resulting in volatile fluctuations of basic and diluted earnings (loss) per share. Readers of this Form 10-Q and investors are cautioned not to place undue reliance on the Company's income (loss) allocations or earnings (loss) per share without considering the effects described above, including the effect that depreciation and amortization have on income (loss), net book value and the application of the HLBV method.
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The Company has cash flow hedge derivative instruments that are measured at fair value with unrealized gains or losses recognized in other comprehensive income (loss) with a corresponding adjustment to accumulated other comprehensive loss within equity, as discussed further in Note 11 . Under the HLBV method of allocating income (loss) discussed above, a calculation is prepared at each balance sheet date by applying the HLBV method including, and excluding, the assets and liabilities resulting from the Company's cash flow hedge derivative instruments to determine comprehensive income (loss) attributable to National Storage Affiliates Trust. As a result of the distribution rights and priorities set forth in the operating partnership's LP Agreement, in any given period, other comprehensive income (loss) may be allocated disproportionately to unitholders as compared to their respective ownership percentage in the operating partnership and as compared to their respective allocation of net income (loss).
Assets Held For Sale	Assets held for sale The Company classifies properties as held for sale when certain criteria are met. At such time, the properties, including significant assets and liabilities that are expected to be transferred as part of a sale transaction, are presented separately on the consolidated balance sheet at the lower of carrying value or estimated fair value less costs to sell and depreciation is no longer recognized. As of September 30, 2016 , the Company had three self storage properties classified as held for sale. These properties were part of a larger portfolio of properties acquired during the third quarter of 2016 whereby the Company decided during the underwriting process to pursue the sale of certain properties following the acquisition. As of December 31, 2015 the Company had no self storage properties classified as held for sale. The results of operations for the self storage properties classified as held for sale are reflected within income from operations in the Company's consolidated statements of operations.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued ASU 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 will replace most existing revenue recognition guidance in GAAP when it becomes effective. ASU 2014-09 is effective for the Company on January 1, 2018, with early application permitted for the Company on January 1, 2017. ASU 2014-09 permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting. In February 2015, the FASB issued ASU 2015-02, Amendments to the Consolidation Analysis, which modifies the current consolidation guidance. Under this guidance, limited partnerships may no longer be viewed as VIEs if the limited partners hold certain rights over the general partner. Alternatively, limited partnerships not previously viewed as VIEs may now be considered VIEs in the absence of such rights. The Company adopted ASU 2015-02 during the nine months ended September 30, 2016 , as more fully described above, see " –Principles of Consolidation". In April 2015, the FASB issued ASU 2015-03, Interest—Imputation of Interest, which requires the presentation of debt issuance costs as a direct deduction from the carrying amount of the related debt liabilities. In August 2015, the FASB issued ASU 2015-15 that permits debt issuance costs related to line-of-credit arrangements to be presented as an asset and amortized over the term of the line-of-credit arrangement regardless of whether there are any outstanding borrowings on the line-of-credit arrangement. The Company adopted ASUs 2015-03 and 2015-15 as of January 1, 2016. The adoption resulted in the reclassification of certain debt issuance costs from assets to a reduction in the carrying amount of the Company's debt financings applied retrospectively to all periods. These reclassifications totaled $5.4 million and $2.8 million as of September 30, 2016 and December 31, 2015, respectively. Debt issuance costs related to the Company's revolving credit facility (the "Revolver") remain classified within "Debt issuance costs, net" in the Company's consolidated balance sheets. In February 2016, the FASB issued ASU 2016-02, Leases, which amends the existing guidance for accounting for leases, including requiring lessors to account for leases using an approach that is substantially equivalent to existing guidance for sales-type leases, direct financing leases and operating leases and lessees to recognize most leases on-balance sheet as lease liabilities with corresponding right-of-use assets. ASU 2016-02 is effective for the Company on January 1, 2019, with early application permitted. ASU 2016-02 requires a modified retrospective approach, with entities applying the new guidance at the beginning of the earliest period presented in the financial statements in which they first apply the new standard, with certain elective transition relief. The Company is evaluating the effect that ASU 2016-02 will have on its operating leases, consolidated financial statements and related disclosures. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows, which clarifies the classification of certain cash receipts and cash payments in the statement of cash flows, including debt prepayment or extinguishment costs, settlement of contingent consideration arising from a business combination, insurance settlement proceeds, and distributions from certain equity method investees. The new standard is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2017. Early adoption is permitted. The Company is evaluating the effect that ASU 2016-15 will have on its consolidated financial statements and related disclosures.

NONCONTROLLING INTERESTS (Table

NONCONTROLLING INTERESTS (Tables)	9 Months Ended
	Sep. 30, 2016
Noncontrolling Interest [Abstract]
Schedule of outstanding equity interests	As of September 30, 2016 and December 31, 2015 , units reflecting noncontrolling interests consisted of the following: September 30, December 31, 2016 2015 OP units 25,503,628 21,556,006 Subordinated performance units 11,011,649 9,302,989 LTIP units 1,552,905 2,784,761 DownREIT units DownREIT OP units 1,834,786 1,834,786 DownREIT subordinated performance units 4,386,999 4,386,999 Total 44,289,967 39,865,541

SELF STORAGE PROPERTIES (Tables

SELF STORAGE PROPERTIES (Tables)	9 Months Ended
	Sep. 30, 2016
Real Estate [Abstract]
Schedule of self storage properties	Self storage properties are summarized as follows (dollars in thousands): September 30, December 31, 2016 2015 Land $ 419,219 $ 315,867 Buildings and improvements 1,196,142 829,093 Furniture and equipment 3,653 2,241 Total self storage properties 1,619,014 1,147,201 Less accumulated depreciation (97,993 ) (68,100 ) Self storage properties, net $ 1,521,021 $ 1,079,101

SELF STORAGE PROPERTY ACQUISI23

SELF STORAGE PROPERTY ACQUISITIONS (Tables)	9 Months Ended
	Sep. 30, 2016
Business Combinations [Abstract]
Schedule of business combinations	The following table summarizes the consideration for the business combinations completed by the Company during the nine months ended September 30, 2016 (dollars in thousands): Acquisitions Closed During the Three Months Ended: Number of Properties Summary of Consideration Value of OP Equity (1) Liabilities Assumed (Assets Acquired) Total Fair Value Cash Mortgages (2) Other March 31, 2016 17 $ 63,300 $ 19,068 $ 5,861 $ 584 $ 88,813 June 30, 2016 25 61,263 80,986 55,767 1,212 199,228 September 30, 2016 34 199,890 4,841 — 896 205,627 Total 76 $ 324,453 $ 104,895 $ 61,628 $ 2,692 $ 493,668 (1) Value of OP equity represents the fair value of OP units, subordinated performance units and LTIP units. (2) $12.2 million of the mortgages assumed in connection with self storage property acquisitions were subsequently repaid during the nine months ended September 30, 2016 .
Schedule of pro forma information	The following table summarizes on a pro forma basis the results of operations for the three and nine months ended September 30, 2016 and 2015 (dollars in thousands): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Pro forma total revenue: Historical results 52,949 35,678 139,882 95,619 Acquisitions subsequent to September 30, 2016 419 382 1,206 976 Acquisitions during the three months ended September 30, 2016 (1) 1,664 4,393 11,317 13,177 Acquisitions during the three months ended June 30, 2016 — 5,053 5,894 14,791 Acquisitions during the three months ended March 31, 2016 (2) — 1,865 842 5,455 Acquisitions during the three months ended September 30, 2015 (3) — 109 — 537 Acquisitions during the three months ended June 30, 2015 — — — 3,782 Acquisitions during the three months ended March 31, 2015 — — — 86 Total $ 55,032 $ 47,480 $ 159,141 $ 134,423 Pro forma net income (loss): (4) Historical results 7,944 2,109 18,791 (569 ) Acquisitions subsequent to September 30, 2016 77 (98 ) 153 (440 ) Acquisitions during the three months ended September 30, 2016 (1) 759 (1,214 ) 1,781 (3,608 ) Acquisitions during the three months ended June 30, 2016 1,268 (610 ) 5,758 (2,177 ) Three Months Ended Nine Months Ended 2016 2015 2016 2015 Acquisitions during the three months ended March 31, 2016 (2) 478 (70 ) 2,548 (2,162 ) Acquisitions during the three months ended September 30, 2015 (3) 34 53 169 3,047 Acquisitions during the three months ended June 30, 2015 — 472 1,055 2,764 Acquisitions during the three months ended March 31, 2015 — 317 53 1,525 Total $ 10,560 $ 959 $ 30,308 $ (1,620 ) (1) Reflects 32 of the 34 self storage properties acquired during this period because the information required with respect to the two remaining acquisitions during this period is not available to the Company. (2) Reflects 15 of the 17 self storage properties acquired during this period because the information required with respect to the two remaining acquisitions during this period is not available to the Company. (3) Reflects one of the 15 self storage properties acquired during this period because the information required with respect to the 14 remaining acquisitions during this period is not available to the Company. (4) Significant assumptions and adjustments in preparation of the pro forma information include the following: (i) for the cash portion of the purchase price, the Company assumed borrowings under the Company's revolving line of credit with interest computed based on the effective interest rate of 1.93% as of September 30, 2016 ; (ii) for assumed debt financing directly associated with the acquisition of specific self storage properties, interest was computed for the entirety of the periods presented using the effective interest rates under such financings; and (iii) for acquisition costs of $4.7 million incurred during the nine months ended September 30, 2016 , pro forma adjustments give effect to these costs as if they were incurred on January 1, 2015.

OTHER ASSETS (Tables)

OTHER ASSETS (Tables)	9 Months Ended
	Sep. 30, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of other assets	Other assets consist of the following (dollars in thousands): September 30, December 31, 2016 2015 Customer in-place leases, net of accumulated amortization of $6,268 and $4,312, respectively $ 7,832 $ 4,209 Receivables: Trade, net 1,562 1,093 PROs and other affiliates 438 232 Investments in and advances to unconsolidated joint venture 5,123 — Property acquisition and other deposits 5,547 763 Interest rate derivative assets — 331 Prepaid expenses and other 2,047 1,486 Corporate furniture, equipment and other, net 822 534 Total $ 23,371 $ 8,648

DEBT FINANCING (Tables)

DEBT FINANCING (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Schedule of debt	The Company's outstanding debt as of September 30, 2016 and December 31, 2015 is summarized as follows (dollars in thousands): Interest September 30, December 31, Rate (1) 2016 2015 Credit Facility: Revolving line of credit 1.93% $ 85,500 $ 187,975 Term loan A 2.61% 225,000 200,000 Term loan B 3.15% 100,000 — Term loan facility 3.08% 100,000 — Fixed rate mortgages payable 4.05% 206,087 176,911 Total principal 716,587 564,886 Unamortized debt issuance costs and debt premium, net 6,035 2,909 Total debt $ 722,622 $ 567,795 (1) Represents the effective interest rate as of September 30, 2016 . Effective interest rate incorporates the stated rate plus the impact of interest rate cash flow hedges and discount and premium amortization, if applicable. For the revolving line of credit, the effective interest rate excludes fees for unused borrowings.
Schedule of future debt maturities	Based on existing debt agreements in effect as of September 30, 2016 , the scheduled principal and maturity payments for outstanding borrowings under the Company's credit facility and fixed rate mortgages are presented in the table below (in thousands): Year Ending December 31, Scheduled Principal and Maturity Payments Premium Amortization and Unamortized Debt Issuance Costs Total Remainder of 2016 $ 2,001 $ 249 $ 2,250 2017 17,495 611 18,106 2018 10,617 514 11,131 2019 4,983 446 5,429 2020 124,745 94 124,839 2021 232,509 (5 ) 232,504 Thereafter 324,237 4,126 328,363 $ 716,587 $ 6,035 $ 722,622

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Schedule of elements used in calculating basic and diluted earnings per common share	The following table sets forth the computation of basic and diluted earnings (loss) per common share for the three and nine months ended September 30, 2016 and 2015 , respectively (in thousands, except per share amounts): Three Months Ended Nine Months Ended 2016 2015 2016 2015 Earnings (loss) per common share - basic and diluted Numerator Net income (loss) $ 7,944 $ 2,109 $ 18,791 $ (569 ) Net (income) loss attributable to noncontrolling interests (7,955 ) 2,263 (9,222 ) 8,405 Net (loss) income attributable to National Storage Affiliates Trust (11 ) 4,372 9,569 7,836 Distributed and undistributed earnings allocated to participating securities (4 ) (3 ) (13 ) (6 ) Net (loss) income attributable to common shareholders - basic (15 ) 4,369 9,556 7,830 Effect of assumed conversion of dilutive securities — (2,275 ) 9,135 (5,646 ) Net (loss) income attributable to common shareholders - diluted $ (15 ) $ 2,094 $ 18,691 $ 2,184 Denominator Weighted average shares outstanding - basic 35,080 23,000 27,084 12,924 Effect of dilutive securities: Weighted average OP units outstanding — 21,109 23,761 13,773 Weighted average DownREIT OP unit equivalents outstanding — 1,432 1,835 949 Weighted average LTIP units outstanding — 1,844 2,162 1,030 Weighted average subordinated performance units and DownREIT subordinated performance unit equivalents — 16,071 20,650 10,082 Weighted average shares outstanding - diluted 35,080 63,456 75,492 38,758 Earnings (loss) per share - basic $ — $ 0.19 $ 0.35 $ 0.61 Earnings (loss) per share - diluted $ — $ 0.03 $ 0.25 $ 0.06

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Schedule of interest rate swap derivatives fair value	Information regarding the Company's interest rate swaps measured at fair value, which are classified within Level 2 of the GAAP fair value hierarchy, is presented below (dollars in thousands): Interest Rate Swaps Designated as Cash Flow Hedges Non-hedge Accounting Interest Rate Swaps Total Fair value at December 31, 2014 $ (865 ) $ (207 ) $ (1,072 ) Unrealized losses included in interest expense — (63 ) (63 ) Designation of interest rate swap as a cash flow hedge (270 ) 270 — Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss 1,182 — 1,182 Unrealized losses included in accumulated other comprehensive loss (2,528 ) — (2,528 ) Fair value at September 30, 2015 $ (2,481 ) $ — $ (2,481 ) Interest Rate Swaps Designated as Cash Flow Hedges Non-hedge Accounting Interest Rate Swaps Total Fair value at December 31, 2015 $ (972 ) $ — $ (972 ) Swap ineffectiveness 11 — 11 Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss 1,829 — 1,829 Unrealized losses included in accumulated other comprehensive loss (8,194 ) — (8,194 ) Fair value at September 30, 2016 $ (7,326 ) $ — $ (7,326 )

ORGANIZATION AND NATURE OF OP28

ORGANIZATION AND NATURE OF OPERATIONS (Details) $ / shares in Units, storage_unit in Thousands, $ in Thousands, ft² in Millions	Jul. 06, 2016USD ($)$ / sharesshares	Apr. 28, 2015USD ($)$ / sharesshares	Sep. 30, 2016USD ($)ft²storage_unitstateproperty$ / sharesshares	Sep. 30, 2015USD ($)	Dec. 31, 2015$ / shares
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Common shares of beneficial interest, par value (in dollars per share) | $ / shares			$ 0.01		$ 0.01
Proceeds from issuance of common shares | $	$ 237,500		$ 238,712	$ 278,070
Number of self storage properties | property			352
Number of states that self storage properties are owned in | state			19
Total rentable square feet in self storage properties | ft²			21
Number of storage units owned | storage_unit			168
Common Shares [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Issuance of common shares (in shares) | shares			12,046,250
Common shares of beneficial interest, par value (in dollars per share) | $ / shares			$ 0.01
Net proceeds from issuance of common shares in IPO | $		$ 278,100
IPO [Member] | Common Shares [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Issuance of common shares (in shares) | shares		23,000,000
Public offering share price (in dollars per share) | $ / shares		$ 13
Over-Allotment Option [Member] | Common Shares [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Issuance of common shares (in shares) | shares	1,571,250	3,000,000
Follow On Offering [Member] | Common Shares [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Issuance of common shares (in shares) | shares	12,046,250
Public offering share price (in dollars per share) | $ / shares	$ 20.75

SUMMARY OF SIGNIFICANT ACCOUN29

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	Sep. 30, 2016USD ($)partnershipproperty	Dec. 31, 2015USD ($)property
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt issuance costs reclassed from assets to liabilities following adoption of ASU 2015-03	$ 2,911	$ 1,923
Variable Interest Entity [Line Items]
Number of properties held for sale | property	3	0
Number of self storage properties owned by VIEs | property	352
Net book value of real estate owned by consolidated VIEs	$ 1,521,021	$ 1,079,101
Carrying value of fixed rate mortgages held by VIEs	716,587	564,886
Mortgages [Member] | Fixed Rate Mortgages [Member]
Variable Interest Entity [Line Items]
Carrying value of fixed rate mortgages held by VIEs	$ 206,087	176,911
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Number of partnerships considered variable interest entities | partnership	21
Number of self storage properties owned by VIEs | property	34
Net book value of real estate owned by consolidated VIEs	$ 258,000	262,600
Variable Interest Entity, Primary Beneficiary [Member] | Mortgages [Member] | Fixed Rate Mortgages [Member]
Variable Interest Entity [Line Items]
Carrying value of fixed rate mortgages held by VIEs	41,900	43,200
Accounting Standards Updated 2015-03 [Member] | Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt issuance costs reclassed from assets to liabilities following adoption of ASU 2015-03	(5,400)	(2,800)
Accounting Standards Updated 2015-03 [Member] | Debt Financing [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt issuance costs reclassed from assets to liabilities following adoption of ASU 2015-03	$ 5,400	$ 2,800

NONCONTROLLING INTERESTS - Equi

NONCONTROLLING INTERESTS - Equity Interests (Details) - shares	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Partnership Subsidiaries [Member]
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	44,289,967	39,865,541
OP units [Member]
Noncontrolling Interest [Line Items]
Shares issued in conversion (in shares)	1,293,860
OP units [Member] | NSA OP, LP [Member]
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	25,503,628	21,556,006
Number of units issued (in shares)	3,499,542
Redemption of Units (in shares)	845,780
OP units [Member] | DownREIT Partnership [Member]
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	1,834,786	1,834,786
Subordinated performance units [Member] | NSA OP, LP [Member]
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	11,011,649	9,302,989
Subordinated performance units [Member] | DownREIT Partnership [Member]
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	4,386,999	4,386,999
LTIP units [Member]
Noncontrolling Interest [Line Items]
Number of units issued (in shares)	180,304
Share converted (in shares)	1,293,860
Shares forfeited (in shares)	118,300
LTIP units [Member] | NSA OP, LP [Member]
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	1,552,905	2,784,761

SELF STORAGE PROPERTIES (Detail

SELF STORAGE PROPERTIES (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Real Estate [Abstract]
Land	$ 419,219		$ 419,219		$ 315,867
Buildings and improvements	1,196,142		1,196,142		829,093
Furniture and equipment	3,653		3,653		2,241
Total self storage properties	1,619,014		1,619,014		1,147,201
Less accumulated depreciation	(97,993)		(97,993)		(68,100)
Self storage properties, net	1,521,021		1,521,021		$ 1,079,101
Depreciation expense related to self storage properties	$ 11,100	$ 7,400	$ 29,900	$ 20,300

SELF STORAGE PROPERTY ACQUISI32

SELF STORAGE PROPERTY ACQUISITIONS - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended						9 Months Ended
	Nov. 04, 2016property	Sep. 30, 2016USD ($)property	Jun. 30, 2016property	Mar. 31, 2016property	Sep. 30, 2015USD ($)property	Jun. 30, 2015property	Mar. 31, 2015property	Sep. 30, 2016USD ($)property	Sep. 30, 2015USD ($)
Business Acquisition [Line Items]
Number of self storage properties acquired | property		34	25	17	15	21	6	76
Estimated fair value of acquired self storage properties		$ 493,700						$ 493,700
Recognized fair value allocated to real estate		481,300						481,300
Revenue from acquired properties since acquisition		11,200						19,400
Operating income from acquired properties since acquisition		1,300						2,200
Acquisition costs		$ 1,737			$ 2,874			4,733	$ 4,192
Number of businesses acquired for which pro forma financial information is available | property		32		15	1
Number of businesses acquired for which pro forma financial information is not available | property		2		2	14
Subsequent Event [Member] | Subsequent Acquisitions [Member]
Business Acquisition [Line Items]
Number of self storage properties acquired | property	2
Leases, Acquired-in-Place [Member]
Business Acquisition [Line Items]
Recognized fair value allocated to in-place leases		$ 12,400						$ 12,400
Affiliated Entity [Member] | Participating Regional Operator [Member]
Business Acquisition [Line Items]
Number of self storage properties acquired | property								21
Estimated fair value of acquired self storage properties		$ 157,600						$ 157,600

SELF STORAGE PROPERTY ACQUISI33

SELF STORAGE PROPERTY ACQUISITIONS - Business Combination Consideration (Details) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2016USD ($)property	Jun. 30, 2016USD ($)property	Mar. 31, 2016USD ($)property	Sep. 30, 2015property	Jun. 30, 2015property	Mar. 31, 2015property	Sep. 30, 2016USD ($)property
Business Combinations [Abstract]
Number of self storage properties acquired | property	34	25	17	15	21	6	76
Consideration given, cash	$ 199,890	$ 61,263	$ 63,300				$ 324,453
Consideration given, value of OP Equity	4,841	80,986	19,068				104,895
Liabilities assumed, mortgages	0	55,767	5,861				61,628
Liabilities assumed, other	896	1,212	584				2,692
Total consideration given and liabilities assumed	$ 205,627	$ 199,228	$ 88,813				493,668
Repayment of assumed mortgages							$ 12,200

SELF STORAGE PROPERTY ACQUISI34

SELF STORAGE PROPERTY ACQUISITIONS - Pro Forma Information (Details) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2016USD ($)property	Jun. 30, 2016property	Mar. 31, 2016property	Sep. 30, 2015USD ($)property	Jun. 30, 2015property	Mar. 31, 2015property	Sep. 30, 2016USD ($)property	Sep. 30, 2015USD ($)	Dec. 31, 2015
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	$ 55,032			$ 47,480			$ 159,141	$ 134,423
Pro forma net income (loss)	$ 10,560			$ 959			$ 30,308	(1,620)
Number of self storage properties acquired | property	34	25	17	15	21	6	76
Number of businesses acquired for which pro forma financial information is available | property	32		15	1
Number of businesses acquired for which pro forma financial information is not available | property	2		2	14
Acquisition costs	$ 1,737			$ 2,874			$ 4,733	4,192
Credit Facility [Member] | Line of Credit [Member] | Revolving line of credit [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Effective interest rate	1.93%						1.93%		1.93%
Subsequent Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	$ 419			382			$ 1,206	976
Pro forma net income (loss)	77			(98)			153	(440)
July To September 2016 Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	1,664			4,393			11,317	13,177
Pro forma net income (loss)	759			(1,214)			1,781	(3,608)
April To June 2016 Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	0			5,053			5,894	14,791
Pro forma net income (loss)	1,268			(610)			5,758	(2,177)
January To March 2016 Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	0			1,865			842	5,455
Pro forma net income (loss)	478			(70)			$ 2,548	(2,162)
Number of self storage properties acquired | property							17
Number of businesses acquired for which pro forma financial information is available | property							15
Number of businesses acquired for which pro forma financial information is not available | property							2
July To September 2015 Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	0			109			$ 0	537
Pro forma net income (loss)	34			53			169	3,047
April To June 2015 Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	0			0			0	3,782
Pro forma net income (loss)	0			472			1,055	2,764
January To March 2015 Acquisitions [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	0			0			0	86
Pro forma net income (loss)	0			317			53	1,525
Consolidated Entities Excluding Acquirees [Member]
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue	52,949			35,678			139,882	95,619
Pro forma net income (loss)	$ 7,944			$ 2,109			$ 18,791	$ (569)

OTHER ASSETS (Details)

OTHER ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Customer in-place leases, net of accumulated amortization of $6,268 and $4,312, respectively	$ 7,832	$ 4,209
Receivables:
Trade, net	1,562	1,093
PROs and other affiliates	438	232
Investments in and advances to unconsolidated joint venture	5,123	0
Property acquisition and other deposits	5,547	763
Interest rate derivative assets	0	331
Prepaid expenses and other	2,047	1,486
Corporate furniture, equipment and other, net	822	534
Total	23,371	8,648
Customer in-place leases, accumulated amortization	$ 6,268	$ 4,312

DEBT FINANCING - Debt Summary (

DEBT FINANCING - Debt Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total principal	$ 716,587	$ 564,886
Unamortized debt issuance costs and debt premium, net	6,035	2,909
Total debt	$ 722,622	$ 567,795
Line of Credit [Member] | Credit Facility [Member] | Revolving line of credit [Member]
Debt Instrument [Line Items]
Effective interest rate	1.93%	1.93%
Total principal	$ 85,500	$ 187,975
Line of Credit [Member] | Credit Facility [Member] | Tranche A Term Loan [Member]
Debt Instrument [Line Items]
Effective interest rate	2.61%	2.61%
Total principal	$ 225,000	$ 200,000
Line of Credit [Member] | Credit Facility [Member] | Tranche B Term Loan [Member]
Debt Instrument [Line Items]
Effective interest rate	3.15%	3.15%
Total principal	$ 100,000	$ 0
Unsecured Debt [Member] | Term Loan Facility [Member]
Debt Instrument [Line Items]
Effective interest rate	3.08%	3.08%
Total principal	$ 100,000	$ 0
Mortgages [Member] | Fixed Rate Mortgages [Member]
Debt Instrument [Line Items]
Effective interest rate	4.05%	4.05%
Total principal	$ 206,087	$ 176,911

DEBT FINANCING - Future maturit

DEBT FINANCING - Future maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Scheduled Principal and Maturity Payments
Remainder of 2016	$ 2,001
2,017	17,495
2,018	10,617
2,019	4,983
2,020	124,745
2,021	232,509
Thereafter	324,237
Total principal	716,587	$ 564,886
Premium Amortization and Unamortized Debt Issuance Costs
Remainder of 2016	249
2,017	611
2,018	514
2,019	446
2,020	94
2,021	(5)
Thereafter	4,126
Total premium amortization and unamortized debt issuance costs	6,035
Total
Remainder of 2016	2,250
2,017	18,106
2,018	11,131
2,019	5,429
2,020	124,839
2,021	232,504
Thereafter	328,363
Total debt	$ 722,622	$ 567,795

DEBT FINANCING - Narrative (Det

DEBT FINANCING - Narrative (Details)	Jun. 30, 2016USD ($)	May 06, 2016USD ($)componentagency	Sep. 30, 2016USD ($)
Line of Credit [Member] | Credit Facility [Member]
Debt Instrument [Line Items]
Increase in credit facility		$ 125,000,000
Current borrowing capacity		$ 675,000,000
Number of lender agreement components | component		3
Debt instrument, covenant compliance, maximum leverage ratio		60.00%
Debt instrument, covenant compliance, minimum interest coverage ratio		1.5
Debt instrument, covenant compliance, required minimum net worth		$ 682,600,000
Debt instrument, covenant compliance, required minimum net worth, addition to base, percent of equity issuances		75.00%
Debt instrument, covenant compliance, maximum unsecured debt to unencumbered asset ratio		60.00%
Debt instrument, covenant compliance, unencumbered net operating income to unsecured interest expense ratio		2
Line of Credit [Member] | Credit Facility [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Borrowing rate spread		0.50%
Line of Credit [Member] | Credit Facility [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Borrowing rate spread		1.00%
Line of Credit [Member] | Credit Facility [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Minimum rating agencies required to verify investment grade rating | agency		2
Line of Credit [Member] | Credit Facility [Member] | Minimum [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Leverage based margin threshold		1.35%
Elective leverage based margin threshold		0.85%
Line of Credit [Member] | Credit Facility [Member] | Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Leverage based margin threshold		0.35%
Elective leverage based margin threshold		0.00%
Line of Credit [Member] | Credit Facility [Member] | Maximum [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Leverage based margin threshold		2.15%
Elective leverage based margin threshold		2.30%
Line of Credit [Member] | Credit Facility [Member] | Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Leverage based margin threshold		1.15%
Elective leverage based margin threshold		1.30%
Line of Credit [Member] | Credit Facility [Member] | Revolving line of credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 350,000,000
Revolver extension fee, percent			0.15%
Remaining borrowing capacity			$ 264,500,000
Line of Credit [Member] | Credit Facility [Member] | Revolving line of credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Elective unused borrowing capacity fee		0.15%
Unused borrowing capacity fee		$ 0.00125
Line of Credit [Member] | Credit Facility [Member] | Revolving line of credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Elective unused borrowing capacity fee		0.25%
Unused borrowing capacity fee		$ 0.003
Line of Credit [Member] | Credit Facility [Member] | Tranche A Term Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		225,000,000
Line of Credit [Member] | Credit Facility [Member] | Tranche B Term Loan [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 100,000,000
Unsecured Debt [Member] | Term Loan Facility [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 100,000,000
Unsecured Debt [Member] | Term Loan Facility [Member] | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Borrowing rate spread	0.50%
Unsecured Debt [Member] | Term Loan Facility [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Borrowing rate spread	1.00%
Unsecured Debt [Member] | Term Loan Facility [Member] | Minimum [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Leverage based margin threshold	1.75%
Elective leverage based margin threshold	1.50%
Unsecured Debt [Member] | Term Loan Facility [Member] | Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Leverage based margin threshold	0.75%
Elective leverage based margin threshold	0.50%
Unsecured Debt [Member] | Term Loan Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 200,000,000
Unsecured Debt [Member] | Term Loan Facility [Member] | Maximum [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Leverage based margin threshold	2.35%
Elective leverage based margin threshold	2.45%
Unsecured Debt [Member] | Term Loan Facility [Member] | Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Leverage based margin threshold	1.35%
Elective leverage based margin threshold	1.45%
Mortgages [Member] | Fixed Rate Mortgages [Member]
Debt Instrument [Line Items]
Minimum effective interest rate			2.44%
Maximum effective interest rate			5.00%

EARNINGS PER SHARE - Basic and

EARNINGS PER SHARE - Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator
Net income (loss)	$ 7,944	$ 2,109	$ 18,791	$ (569)
Net (income) loss attributable to noncontrolling interests	(7,955)	2,263	(9,222)	8,405
Net (loss) income attributable to National Storage Affiliates Trust	(11)	4,372	9,569	7,836
Distributed and undistributed earnings allocated to participating securities	(4)	(3)	(13)	(6)
Net (loss) income attributable to common shareholders - basic	(15)	4,369	9,556	7,830
Effect of assumed conversion of dilutive securities	0	(2,275)	9,135	(5,646)
Net (loss) income attributable to common shareholders - diluted	$ (15)	$ 2,094	$ 18,691	$ 2,184
Denominator
Weighted average shares outstanding - basic (in shares)	35,080	23,000	27,084	12,924
Effect of dilutive securities:
Weighted average shares outstanding - diluted (in shares)	35,080	63,456	75,492	38,758
Earnings (loss) per share - basic (in dollars per share)	$ 0	$ 0.19	$ 0.35	$ 0.61
Earnings (loss) per share - diluted (in dollars per share)	$ 0	$ 0.03	$ 0.25	$ 0.06
OP units [Member] | NSA OP, LP [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	0	21,109	23,761	13,773
OP units [Member] | DownREIT Partnership [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	0	1,432	1,835	949
LTIP units [Member] | NSA OP, LP [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	0	1,844	2,162	1,030
Subordinated performance units [Member] | NSA OP, LP And DownREIT Partnership [Member]
Effect of dilutive securities:
Effect of dilutive securities (in shares)	0	16,071	20,650	10,082

EARNINGS PER SHARE - Narrative

EARNINGS PER SHARE - Narrative (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2016shares	Sep. 30, 2016unit / sharesshares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average outstanding equity interests excluded from computation of earnings (in units) | shares	49,800,000
NSA OP, LP [Member] | OP units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Unit conversion ratio | unit / shares		1
DownREIT Partnership [Member] | OP units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Unit conversion ratio | unit / shares		1
NSA OP, LP And DownREIT Partnership [Member] | Subordinated performance units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Unit conversion ratio | unit / shares		1
Minimum conversion period		2 years
Long-Term Incentive Plan Unit Based On Service [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average outstanding equity interests excluded from computation of earnings (in units) | shares	386,713	386,713
Long-Term Incentive Plan Unit Based On Future Acquisitions [Member] | Participating Regional Operator [Member] | Management [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted average outstanding equity interests excluded from computation of earnings (in units) | shares	397,600	271,400

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Related Party Transaction [Line Items]
Affiliate payroll service fees reimbursed by the Company	$ 17,330	$ 12,000	$ 46,064	$ 32,668
Supervisory and Administrative Fee Agreement [Member] | Participating Regional Operator [Member] | Management [Member]
Related Party Transaction [Line Items]
Supervisory and administrative fees for PROs	3,000	2,000	7,800	5,400
Payroll Services [Member] | Participating Regional Operator [Member] | Management [Member]
Related Party Transaction [Line Items]
Affiliate payroll service fees reimbursed by the Company	5,100	3,500	13,800	9,600
Due Diligence Costs [Member] | Participating Regional Operator [Member] | Management [Member] | Acquisition Costs [Member]
Related Party Transaction [Line Items]
Due diligence expenses payable to the PROs	$ 400	$ 300	$ 700	$ 400
Minimum [Member] | Supervisory and Administrative Fee Agreement [Member] | Participating Regional Operator [Member] | Management [Member]
Related Party Transaction [Line Items]
Supervisory and administrative fee agreement of gross revenue, percent			5.00%
Maximum [Member] | Supervisory and Administrative Fee Agreement [Member] | Participating Regional Operator [Member] | Management [Member]
Related Party Transaction [Line Items]
Supervisory and administrative fee agreement of gross revenue, percent			6.00%

FAIR VALUE MEASUREMENTS - Inter

FAIR VALUE MEASUREMENTS - Interest Swap Derivatives (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis [Roll Forward]
Designation of interest rate swap as a cash flow hedge		$ 0
Interest Rate Swap [Member] | Level 2 [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis [Roll Forward]
Fair value at beginning of period	$ (972)	(1,072)
Unrealized losses included in interest expense		(63)
Swap ineffectiveness	11
Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss	1,829	1,182
Unrealized losses included in accumulated other comprehensive loss	(8,194)	(2,528)
Fair value of end of period	(7,326)	(2,481)
Interest Rate Swap [Member] | Level 2 [Member] | Designated as Hedging Instrument [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis [Roll Forward]
Fair value at beginning of period	(972)	(865)
Unrealized losses included in interest expense		0
Designation of interest rate swap as a cash flow hedge		(270)
Swap ineffectiveness	11
Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss	1,829	1,182
Unrealized losses included in accumulated other comprehensive loss	(8,194)	(2,528)
Fair value of end of period	(7,326)	(2,481)
Interest Rate Swap [Member] | Level 2 [Member] | Not Designated as Hedging Instrument [Member]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis [Roll Forward]
Fair value at beginning of period	0	(207)
Unrealized losses included in interest expense		(63)
Designation of interest rate swap as a cash flow hedge		270
Swap ineffectiveness	0
Losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive loss	0	0
Unrealized losses included in accumulated other comprehensive loss	0	0
Fair value of end of period	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized losses forecasted to be included in earnings transferred from AOCI in the next twelve months	$ 2.8
Level 2 [Member] | Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed rate mortgages, fair value	$ 227.9	$ 189.3
Weighted average market interest rate	3.16%	3.41%
Weighted average contractual interest rate	5.26%	5.10%
Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount	$ 425	$ 199.4
Weighted average remaining term	4 years
Weighted average fixed rate	1.34%
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed rate mortgages, fair value	$ 206.1	$ 176.9

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) $ / shares in Units, storage_unit in Thousands, ft² in Millions	Nov. 01, 2016USD ($)	Oct. 04, 2016USD ($)ft²storage_unitstateproperty$ / property	Jul. 06, 2016USD ($)$ / sharesshares	Nov. 01, 2016USD ($)propertyshares	Oct. 31, 2016USD ($)$ / sharesshares	Sep. 30, 2016USD ($)ft²storage_unitstateproperty	Jun. 30, 2016USD ($)property	Mar. 31, 2016USD ($)property	Sep. 30, 2015property	Jun. 30, 2015property	Mar. 31, 2015property	Sep. 30, 2016USD ($)ft²storage_unitstatepropertyshares	Sep. 30, 2015USD ($)	Oct. 11, 2016USD ($)agent
Subsequent Event [Line Items]
Number of self storage properties acquired | property						34	25	17	15	21	6	76
Cash consideration for acquired self storage properties												$ 323,822,000	$ 132,196,000
Consideration given, value of OP Equity						$ 4,841,000	$ 80,986,000	$ 19,068,000				$ 104,895,000
Number of self storage properties | property						352						352
Total rentable square feet in self storage properties | ft²						21						21
Number of storage units | storage_unit						168						168
Number of states that self storage properties are located in | state						19						19
Proceeds from issuance of common shares			$ 237,500,000									$ 238,712,000	$ 278,070,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Number of agents used in equity sales agreement | agent														4
Common shares authorized (in shares)														$ 200,000,000
Proceeds from issuance of common shares					$ 28,900,000
Subsequent Event [Member] | Series of Individually Immaterial Business Acquisitions [Member]
Subsequent Event [Line Items]
Number of self storage properties acquired | property				2
Aggregate purchase price of businesses acquired subsequent to period end		$ 20,000,000		$ 16,900,000
Cash consideration for acquired self storage properties				10,600,000
Consideration given, value of OP Equity				$ 6,000,000
Other working capital liabilities assumed	$ 300,000
Subsequent Event [Member] | Series of Individually Immaterial Business Acquisitions [Member] | Participating Regional Operator [Member]
Subsequent Event [Line Items]
Number of self storage properties acquired | property				1
Subsequent Event [Member] | Series of Individually Immaterial Business Acquisitions [Member] | Unidentified Third Parties [Member]
Subsequent Event [Line Items]
Number of self storage properties acquired | property				1
OP units [Member] | Subsequent Event [Member] | Series of Individually Immaterial Business Acquisitions [Member]
Subsequent Event [Line Items]
Number of units issued for acquisitions (in shares) | shares				308,345
Due Diligence Costs [Member] | Management [Member] | Subsequent Event [Member] | Participating Regional Operator [Member]
Subsequent Event [Line Items]
Due diligence expenses payable to the PROs				$ 100,000
Joint Venture [Member]
Subsequent Event [Line Items]
Equity method investments						$ 5,100,000						$ 5,100,000
Joint Venture [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Equity method investment, monthly property management fee, percent		6.00%
Equity method investment, annual call center fee, percent		1.00%
Equity method investment, monthly platform fee (in dollars per property) | $ / property		1,250
Equity method investment, acquisition fee, percent		0.65%
Equity method investment, acquisition fee, annual percentage earned		25.00%
Equity method investment, acquisition fee, term		4 years
Equity method investment, development management fee, percent		3.00%
Equity method investment, warranty protection exchange, proceeds given in exchange, percent		50.00%
IStorage Facilities [Member] | Joint Venture [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Aggregate purchase price of JV portfolio		$ 630,000,000
Total equity contributed by JV Partners to Joint Venture		320,000,000
Equity contributed by JV Partner to Joint Venture		$ 80,000,000
Number of self storage properties | property		66
Total rentable square feet in self storage properties | ft²		4.5
Number of storage units | storage_unit		36
Number of states that self storage properties are located in | state		12
Equity method investment, ownership percentage		25.00%
IStorage Facilities [Member] | Joint Venture [Member] | Subsequent Event [Member] | State Pension Fund [Member]
Subsequent Event [Line Items]
Equity contributed by JV Partner to Joint Venture		$ 240,000,000
Equity method investment, ownership percentage		75.00%
Common Shares [Member]
Subsequent Event [Line Items]
Issuance of common shares (in shares) | shares												12,046,250
Common Shares [Member] | Follow On Offering [Member]
Subsequent Event [Line Items]
Issuance of common shares (in shares) | shares			12,046,250
Public offering share price (in dollars per share) | $ / shares			$ 20.75
Common Shares [Member] | Follow On Offering [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Issuance of common shares (in shares) | shares					1,500,000
Public offering share price (in dollars per share) | $ / shares					$ 19.50