0001289490-26-000065 | 10-Q | XBRL Viewer

EARNINGS PER COMMON SHARE - Additional Information (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Earnings Per Share [Abstract]
Average share price (in dollars per share)	$ 143.53	$ 143.62	$ 142.50	$ 146.84

ORGANIZATION	9 Months Ended
ORGANIZATION	Sep. 30, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION	ORGANIZATION Extra Space Storage Inc. (the “Company”) is a fully integrated, self-administered and self-managed real estate investment trust (“REIT”), formed as a Maryland corporation on April 30, 2004, to own, operate, manage, acquire, develop and redevelop self-storage properties (“stores”) and provide lending to owners of stores located throughout the United States. The Company was formed to continue the business of Extra Space Storage LLC and its subsidiaries, which had engaged in the self-storage business since 1977. The Company’s interest in its stores is held through its operating partnership, Extra Space Storage LP (the “Operating Partnership”), which was formed on May 5, 2004. The Company’s primary assets are general partner and limited partner interests in the Operating Partnership, which meets the definition of a variable interest entity and is consolidated. This structure is commonly referred to as an umbrella partnership REIT, or UPREIT. The Company invests in stores by acquiring wholly-owned stores or by acquiring an equity interest in real estate entities. At September 30, 2026, the Company had direct and indirect equity interests in 2,448 stores. In addition, the Company managed 1,963 stores for third parties, bringing the total number of stores which it owns and/or manages to 4,411. These stores are located in 43 states and Washington, D.C. The Company offers tenant reinsurance at its owned and managed stores that insures the value of goods in the storage units and also offers bridge loan financing to third-party self-storage owners primarily for whom it manages properties.

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025
Cash flows from operating activities:
Net income	$ 787,744	$ 721,674
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	561,003	535,088
Amortization of deferred financing costs	9,986	8,757
Non-cash lease expense	9,161	9,661
Non-cash interest expense related to amortization of discount on unsecured senior notes, net	35,001	35,169
Compensation expense related to share-based awards	25,360	22,740
Accrual of interest income added to principal of debt securities and notes receivable	(18,431)	(24,101)
Equity in earnings of unconsolidated real estate ventures - impairment loss on joint venture interests and (gain) on sale of joint venture interests	13,036	(9,354)
Loss on real estate assets held for sale and sold, net	5,821	70,231
Distributions in excess of earnings from unconsolidated real estate ventures	19,934	24,795
Changes in operating assets and liabilities:
Other assets	23,832	(28,098)
Accounts payable and accrued expenses	96,048	121,191
Other liabilities	(25,102)	(5,357)
Net cash provided by operating activities	1,543,393	1,482,396
Cash flows from investing activities:
Acquisition of real estate assets and improvements	(280,857)	(587,547)
Return of investment in unconsolidated real estate ventures	3,154	231,130
Development and redevelopment of real estate assets	(95,117)	(111,067)
Proceeds from sale of real estate assets	17,896	168,747
Investment in unconsolidated real estate entities	(10,198)	(107,178)
Issuance of notes receivable	(245,531)	(512,377)
Payments received on notes receivable	306,187	137,962
Proceeds from sale of notes receivable	30,414	98,372
Purchase of equipment and fixtures	(12,364)	(15,704)
Net cash used in investing activities	(286,416)	(697,662)
Cash flows from financing activities:
Proceeds from secured and unsecured term loans, senior notes, revolving lines of credit and commercial paper	15,949,770	11,436,343
Principal payments on secured and unsecured term loans, senior notes, revolving lines of credit and commercial paper	(15,760,302)	(12,780,602)
Proceeds from issuance of public bonds, net	550,000	1,650,000
Repayment of public bonds	(600,000)	0
Deferred financing costs	(7,681)	(30,698)
Repurchase of common stock	(328,622)	(8,615)
Redemption of Operating Partnership units for cash	(7,655)	(1,453)
Redemption of Preferred OP units for cash	(6,000)	0
Dividends paid on common stock	(1,025,344)	(1,031,930)
Distributions to noncontrolling interests, net of contributions	(44,649)	(44,848)
Net cash used in financing activities	(1,280,483)	(811,803)
Net change in cash, cash equivalents, and restricted cash	(23,506)	(27,069)
Cash, cash equivalents, and restricted cash, beginning of the period	143,180	143,303
Cash, cash equivalents, and restricted cash, end of the period	119,674	116,234
Cash and cash equivalents	114,824	111,931
Restricted cash included in other assets	4,850	4,303
Cash, cash equivalents, and restricted cash	119,674	116,234
Supplemental schedule of cash flow information
Interest paid	448,509	433,412
Redemption of Operating Partnership units held by noncontrolling interests for common stock
Noncontrolling interests in Operating Partnership	0	(26,218)
Common stock and paid-in capital	0	26,218
Remeasurement of lease right of use assets and lease liabilities
Real estate assets - operating lease right-of-use assets	10,525	419
Operating lease liabilities	(10,525)	(419)
Real estate assets, net	(4,586)	0
Other liabilities	4,586	0
Acquisitions of real estate assets
Real estate assets, net	73,134	111,984
Value of OP units issued	0	(5,878)
Value of investment in consolidated real estate ventures	0	(105,471)
Net liabilities assumed	0	(635)
Bridge loan receivable	73,134	0
Accrued construction costs and capital expenditures
Acquisition of real estate assets	5,146	5,121
Accounts payable and accrued expenses	$ (5,146)	$ (5,121)

NONCONTROLLING INTEREST IN OPERATING PARTNERSHIP AND OTHER NONCONTROLLING INTERESTS - Schedule of OP Unit Activity (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Sep. 30, 2025
Noncontrolling Interest [Abstract]
OP Units redeemed for common stock (in shares)	0	41,978
OP Units redeemed for cash (in shares)	53,914	10,000
Cash paid for OP Units redeemed	$ 7,655	$ 1,453
OP Units issued in conjunction with acquisitions (in shares)	0	37,886
Value of OP Units issued in conjunction with acquisitions	$ 0	$ 5,878

EARNINGS PER COMMON SHARE - Schedule of Antidilutive Shares Excluded from Computation of Earnings Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per common share (in shares)	333,227	374,795	338,566	9,747,768
Common OP Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per common share (in shares)	0	0	0	9,357,864
Series B Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per common share (in shares)	233,876	233,729	235,566	228,604
Series D Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per common share (in shares)	99,351	141,066	103,000	161,300

OTHER ASSETS

9 Months Ended

Sep. 30, 2026

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

OTHER ASSETS

The components of other assets are summarized as follows:


	September 30, 2026		December 31, 2025
Goodwill	$	170,811	$	170,811
Receivables, net	116,869		142,120
Prepaid expenses and deposits	101,670		102,656
Equipment and fixtures, net	59,039		65,154
Deferred line of credit financing costs, net	13,302		15,335
Other intangible assets, net	—		11,593
Restricted cash	4,850		4,260
Fair value of interest rate swaps	1,059		3,362
	$	467,600	$	515,291

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2026
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

OTHER ASSETS (Tables)

9 Months Ended

Sep. 30, 2026

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Components of Other Assets

The components of other assets are summarized as follows:


	September 30, 2026		December 31, 2025
Goodwill	$	170,811	$	170,811
Receivables, net	116,869		142,120
Prepaid expenses and deposits	101,670		102,656
Equipment and fixtures, net	59,039		65,154
Deferred line of credit financing costs, net	13,302		15,335
Other intangible assets, net	—		11,593
Restricted cash	4,850		4,260
Fair value of interest rate swaps	1,059		3,362
	$	467,600	$	515,291

ACQUISITIONS AND DISPOSITIONS - Schedule of Operating Properties Acquired (Details) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2026 USD ($) store	Jun. 30, 2026 USD ($) store	Mar. 31, 2026 USD ($) store	Sep. 30, 2025 USD ($) store	Jun. 30, 2025 USD ($) store	Mar. 31, 2025 USD ($) store	Sep. 30, 2026 USD ($) store	Sep. 30, 2025 USD ($) store
Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]
Number of Stores \| store	4	17	1	1	28	17	22	46
Cash Paid	$ 8,081	$ 53,984	$ 12,360	$ 0	$ 161,738	$ 117,075	$ 74,425	$ 278,813
Loans Assumed	0	0	0	0	258,000	0	0	258,000
Bridge Loan Payoff	40,454	32,680	0	12,945	0	18,950	73,134	31,895
Fair Value Adjustment of Debt Assumed	0	0	0	0	(10,049)	0	0	(10,049)
Investments in Real Estate Ventures	0	0	0	0	34,767	105,471	0	140,238
Net Liabilities/ (Assets) Assumed	240	550	148	(30)	4,472	847	938	5,289
Value of Equity Issued	0	0	0	0	0	5,878	0	5,878
Total Real Estate Assets	$ 48,775	$ 87,214	$ 12,508	$ 12,915	$ 448,928	$ 248,221	$ 148,497	$ 710,064

DERIVATIVES (Tables)

9 Months Ended

Sep. 30, 2026

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Balance Sheet Classification and Fair Value of Entity's Derivative Financial Instruments

The table below presents the fair values of the Company’s derivative financial instruments as well as their classification on the condensed consolidated balance sheets:


	Asset / Liability Derivatives
Derivatives designated as hedging instruments:	September 30, 2026		December 31, 2025
Other assets	$	1,059	$	3,362
Other liabilities	$	60	$	2,538

Schedule of Information Relating to Gain (Loss) Recognized on Swap Agreements

The table below presents the effect of the Company’s derivative financial instruments on the condensed consolidated statements of operations for the periods presented. No tax effect has been presented as the derivative instruments are held by the Company:


	Gain (loss) recognized in OCI for the Three Months Ended September 30,				Location of amounts reclassified from OCI into income	Gain (loss) reclassified from OCI for the Three Months Ended September 30,
Type	2026		2025			2026		2025
Swap Agreements	$	329	$	874	Interest expense	$	234	$	2,822
	Gain (loss) recognized in OCI for the Nine Months Ended September 30,				Location of amounts reclassified from OCI into income	Gain (loss) reclassified from OCI for the Nine Months Ended September 30,
Type	2026		2025			2026		2025
Swap Agreements	$	3,099	$	(2,572)	Interest expense	$	2,761	$	9,490

FAIR VALUE DISCLOSURES - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	$ 1,059	$ 3,362
Other liabilities - Cash flow hedge swap agreements	60	$ 2,538
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	0
Other liabilities - Cash flow hedge swap agreements	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	1,059
Other liabilities - Cash flow hedge swap agreements	60
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets - Cash flow hedge swap agreements	0
Other liabilities - Cash flow hedge swap agreements	$ 0

NONCONTROLLING INTEREST IN OPERATING PARTNERSHIP AND OTHER NONCONTROLLING INTERESTS (Tables)

9 Months Ended

Sep. 30, 2026

Noncontrolling Interest [Abstract]

Schedule of Redeemable Noncontrolling Interest

OP Unit activity is summarized as follows for the periods presented:


	For the Nine Months Ended September 30,
	2026		2025
OP Units redeemed for common stock	—		41,978
OP Units redeemed for cash	53,914		10,000
Cash paid for OP Units redeemed	$	7,655	$	1,453
OP Units issued in conjunction with acquisitions	—		37,886
Value of OP Units issued in conjunction with acquisitions	$	—	$	5,878

NONCONTROLLING INTEREST REPRESENTED BY PREFERRED OPERATING PARTNERSHIP UNITS (Tables)

9 Months Ended

Sep. 30, 2026

Noncontrolling Interest [Abstract]

Schedule of Balances of OP Units

The balances for each of the specific Preferred OP Units as presented in the Statements of Noncontrolling Interests and Equity as of the periods indicated are as follows:


	September 30, 2026		December 31, 2025
Series B Units	$	33,567	$	33,567
Series D Units	14,260		20,260
	$	47,827	$	53,827

BASIS OF PRESENTATION	9 Months Ended
BASIS OF PRESENTATION	Sep. 30, 2026
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements of the Company are presented on the accrual basis of accounting in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information, and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they may not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and nine months ended September 30, 2026 are not necessarily indicative of results that may be expected for the year ending December 31, 2026. The condensed consolidated balance sheet as of December 31, 2025 has been derived from the Company’s audited financial statements as of that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. For further information refer to the consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the Securities and Exchange Commission (the “SEC”). Recently Issued Accounting Standards In November 2024, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2024-03 – “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40)”. The guidance requires the disclosure of additional information related to certain costs and expenses, including amounts of inventory purchases, employee compensation, and depreciation and amortization included in each income statement line item. For any remaining items within each relevant expense caption, entities must provide a qualitative description of the nature of those expenses. The guidance also requires disclosure of the total amount of selling expenses and the entity’s definition of selling expenses. The guidance is effective for annual periods beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027; therefore, compliance with this ASU will be required beginning with the Company’s Annual Report on Form 10-K for the year ending December 31, 2027. The guidance may be applied prospectively or retrospectively, and early adoption is permitted. Although the adoption is not expected to have a significant impact on the Company's financial statements, it is expected to result in incremental disclosures within the notes to the financial statements.

INVESTMENTS IN UNCONSOLIDATED REAL ESTATE ENTITIES (Tables)

9 Months Ended

Sep. 30, 2026

Equity Method Investments and Joint Ventures [Abstract]

Schedule of Investments in Unconsolidated Real Estate Ventures

Net investments in unconsolidated real estate entities and cash distributions in unconsolidated real estate ventures consist of the following:


	Number of Stores	Equity Ownership %	Excess Profit % (1)	September 30,		December 31,
				2026		2025
PRISA Self Storage LLC	85	4%	4%	$	8,428	$	8,736
HF1 Sovran HHF Storage Holdings LLC	37	49%	49%-59%	297,606		301,794
Storage Portfolio II JV LLC	36	10%	30%	(11,445)		(10,588)
Storage Portfolio IV JV LLC	32	10%	30%	45,608		46,310
Storage Portfolio I LLC	24	34%	49%	(45,204)		(44,537)
HF2 Sovran HHF Storage Holdings II LLC	22	49%	49%-59%	110,928		112,551
HF5 Life Storage-HIERS Storage LLC	17	20%	20%	23,860		24,580
HF6 191 V Life Storage Holdings LLC	17	20%	20%	7,470		9,525
VRS Self Storage, LLC	16	45%	54%	(19,252)		(18,576)
HF10 Life Storage HHF Wasatch Holdings LLC	16	20%	20%	17,373		18,082
Other unconsolidated real estate ventures (2)	106	10%-50%	10%-50%	284,122		295,205
Strategic Storage Growth Trust III, Inc. Preferred Stock (3)	n/a	n/a	n/a	100,000		100,000
Strategic Storage Trust VI, Inc. Preferred Stock (4)	n/a	n/a	n/a	150,000		150,000
Net Investments in and Cash distributions in unconsolidated real estate entities	408			$	969,494	$	993,082

Investments in unconsolidated real estate entities				$	1,045,395	$	1,066,783
Cash distributions in unconsolidated real estate ventures				(75,901)		(73,701)
Net Investments in and Cash distributions in unconsolidated real estate entities				$	969,494	$	993,082

(1) Includes pro-rata equity ownership share and promoted interest.

(2) During the three months ended September 30, 2026, the Company fully impaired its investments in two joint ventures resulting in a loss of $13,883. This loss is included in the equity in earnings of unconsolidated real estate ventures - impairment (loss) on joint venture interests and gain on sale of joint venture interests line on the Company’s condensed consolidated statements of operations.

(3) On February 4, 2025, the Company invested $100,000 in shares of convertible preferred stock with a dividend rate of 8.85% per annum, subject to increase after five years. The preferred shares are generally not redeemable for five years, except in the case of a change of control or initial listing, and are redeemable thereafter subject to a redemption premium.

(4) In May 2023, the Company invested $150,000 in shares of convertible preferred stock with a dividend rate of 8.35% per annum, subject to increase after five years. The preferred shares are generally not redeemable for three years.

FAIR VALUE DISCLOSURES - Additional Information (Details)	Sep. 30, 2026 store
Fair Value Disclosures [Abstract]
Number of operating stores held-for-sale	4

OTHER ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025	Sep. 30, 2025	Dec. 31, 2024
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Goodwill	$ 170,811	$ 170,811
Receivables, net	116,869	142,120
Prepaid expenses and deposits	101,670	102,656
Equipment and fixtures, net	59,039	65,154
Deferred line of credit financing costs, net	13,302	15,335
Other intangible assets, net	0	11,593
Restricted cash	4,850	4,260	$ 4,303	$ 5,081
Fair value of interest rate swaps	1,059	3,362
Other assets, net	$ 467,600	$ 515,291

REAL ESTATE ASSETS (Tables)

9 Months Ended

Sep. 30, 2026

Real Estate [Abstract]

Schedule of Components of Real Estate Assets

The components of real estate assets are summarized as follows:


	September 30, 2026		December 31, 2025
Land	$	5,155,953	$	5,135,719
Buildings, improvements and other intangibles	23,627,672		23,234,033
Right of use assets - finance lease	136,608		141,194
Intangible assets - tenant relationships	335,955		334,669
Intangible lease rights	37,779		37,771
	29,293,967		28,883,386
Less: accumulated depreciation and amortization	(4,503,974)		(3,982,125)
Net operating real estate assets	24,789,993		24,901,261
Real estate under development/redevelopment	110,154		103,089
Real estate assets, net	$	24,900,147	$	25,004,350

NONCONTROLLING INTEREST IN OPERATING PARTNERSHIP AND OTHER NONCONTROLLING INTERESTS - Additional Information (Details) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended
	Dec. 31, 2024	Sep. 30, 2026 USD ($) store joint_venture $ / shares shares	Dec. 31, 2025 USD ($)
Noncontrolling Interest [Line Items]
Loan receivable, reduction of noncontrolling interests \| $			$ 50,000
Note receivable interest rate	10.00%
Period used as a denomination to determine the average closing price of common stock		10 days
Ten day average closing stock price (in dollars per share) \| $ / shares		$ 134.43
Preferred units outstanding (in shares) \| shares		9,379,076
Consideration to be paid on redemption of common OP units \| $		$ 1,260,829
Number of consolidated joint ventures \| joint_venture		11
Total number of stores in consolidated joint venture \| store		15
Number of joint ventures operating store \| joint_venture		12
Number of joint ventures with property under development \| store		3
Common Stock
Noncontrolling Interest [Line Items]
Unit conversion ratio		1
Operating Partnership
Noncontrolling Interest [Line Items]
Ownership interest held		95.60%
Ownership interest held by joint venture partner		4.40%
Other noncontrolling interests \| Maximum
Noncontrolling Interest [Line Items]
Ownership interest held by joint venture partner		25.00%

COMMITMENTS AND CONTINGENCIES (Details) $ in Thousands	Sep. 30, 2026 USD ($) store
Commitment to acquire stores
Other Commitments [Line Items]
Number of real estate properties to be acquired \| store	3
Other commitment	$ 24,780
Agreement to originate bridge loans
Other Commitments [Line Items]
Purchase price , 2026	59,160
Purchase price , 2027	$ 31,300

COMMITMENTS AND CONTINGENCIES	9 Months Ended
COMMITMENTS AND CONTINGENCIES	Sep. 30, 2026
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES As of September 30, 2026, the Company was under agreement to acquire three stores for a total purchase price of $24,780, which are scheduled to close in 2026. As of September 30, 2026, the Company was under agreement to originate $59,160 in bridge loans in 2026 and $31,300 in 2027. As of September 30, 2026, the Company was involved in various legal proceedings and was subject to various claims and complaints arising in the ordinary course of business. Because litigation is inherently unpredictable, the outcome of these matters cannot presently be determined with any degree of certainty. In accordance with applicable accounting guidance, management establishes an accrued liability for litigation when those matters present loss contingencies that are both probable and reasonably estimable. In such cases, there may be an exposure to loss in excess of any amounts accrued. The estimated loss, if any, is based upon currently available information and is subject to significant judgment, a variety of assumptions, and known and unknown uncertainties. The Company could incur judgments or enter into settlements of claims in the future that could have a material adverse effect on its results of operations in any particular period, notwithstanding the fact that the Company is currently vigorously defending any legal proceedings against it. Although there can be no assurance, the Company is not aware of any material environmental liability, for which it believes it will be ultimately responsible, that could have a material adverse effect on its financial condition or results of operations. However, changes in applicable environmental laws and regulations, the uses and conditions of properties in the vicinity of the Company’s properties, the activities of its tenants and other environmental conditions of which the Company is unaware with respect to its properties could result in future material environmental liabilities.

ORGANIZATION (Details)	Sep. 30, 2026 store
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating storage facilities in which the entity has equity interests (in stores)	2,448
Number of stores owned by franchisees and third parties	1,963
Number of operating stores owned and/or managed	4,411
Number of states in which operating storage facilities are located	43

SEGMENT INFORMATION - Additional Information (Details)	9 Months Ended
SEGMENT INFORMATION - Additional Information (Details)	Sep. 30, 2026 segment
Segment Reporting [Abstract]
Number of reportable segments	2

INVESTMENTS IN UNCONSOLIDATED REAL ESTATE ENTITIES (Details) $ in Thousands		1 Months Ended	3 Months Ended
	Feb. 04, 2025 USD ($)	May 31, 2023 USD ($)	Sep. 30, 2026 USD ($) property	Dec. 31, 2025 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			408
Investment balance			$ 969,494	$ 993,082
Investments in unconsolidated real estate entities			1,045,395	1,066,783
Cash distributions in unconsolidated real estate ventures			$ (75,901)	(73,701)
PRISA Self Storage LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			85
Equity Ownership %			4.00%
Excess Profit %			4.00%
Investment balance			$ 8,428	8,736
HF1 Sovran HHF Storage Holdings LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			37
Equity Ownership %			49.00%
Investment balance			$ 297,606	301,794
HF1 Sovran HHF Storage Holdings LLC \| Minimum
Schedule of Equity Method Investments [Line Items]
Excess Profit %			49.00%
HF1 Sovran HHF Storage Holdings LLC \| Maximum
Schedule of Equity Method Investments [Line Items]
Excess Profit %			59.00%
Storage Portfolio II JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			36
Equity Ownership %			10.00%
Excess Profit %			30.00%
Investment balance			$ (11,445)	(10,588)
Storage Portfolio IV JV LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			32
Equity Ownership %			10.00%
Excess Profit %			30.00%
Investment balance			$ 45,608	46,310
Storage Portfolio I LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			24
Equity Ownership %			34.00%
Excess Profit %			49.00%
Investment balance			$ (45,204)	(44,537)
HF2 Sovran HHF Storage Holdings II LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			22
Equity Ownership %			49.00%
Investment balance			$ 110,928	112,551
HF2 Sovran HHF Storage Holdings II LLC \| Minimum
Schedule of Equity Method Investments [Line Items]
Excess Profit %			49.00%
HF2 Sovran HHF Storage Holdings II LLC \| Maximum
Schedule of Equity Method Investments [Line Items]
Excess Profit %			59.00%
HF5 Life Storage-HIERS Storage LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			17
Equity Ownership %			20.00%
Excess Profit %			20.00%
Investment balance			$ 23,860	24,580
HF6 191 V Life Storage Holdings LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			17
Equity Ownership %			20.00%
Excess Profit %			20.00%
Investment balance			$ 7,470	9,525
VRS Self Storage, LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			16
Equity Ownership %			45.00%
Excess Profit %			54.00%
Investment balance			$ (19,252)	(18,576)
HF10 Life Storage HHF Wasatch Holdings LLC
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			16
Equity Ownership %			20.00%
Excess Profit %			20.00%
Investment balance			$ 17,373	18,082
Other unconsolidated real estate ventures (2)
Schedule of Equity Method Investments [Line Items]
Number of Stores \| property			106
Investment balance			$ 284,122	295,205
Other unconsolidated real estate ventures (2) \| Minimum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			10.00%
Excess Profit %			10.00%
Other unconsolidated real estate ventures (2) \| Maximum
Schedule of Equity Method Investments [Line Items]
Equity Ownership %			50.00%
Excess Profit %			50.00%
Strategic Storage Growth Trust III, Inc. Preferred Stock
Schedule of Equity Method Investments [Line Items]
Investment balance			$ 100,000	100,000
Strategic Storage Trust VI, Inc. Preferred Stock
Schedule of Equity Method Investments [Line Items]
Investment balance			150,000	$ 150,000
Dividend rate, percentage		8.35%
Dividend rate increase, threshold		5 years
Redemption period		3 years
Investment in shares		$ 150,000
Strategic Storage Growth Trust III, Inc.
Schedule of Equity Method Investments [Line Items]
Investment balance	$ 100,000
Dividend rate, percentage	8.85%
Dividend rate increase, threshold	5 years
Redemption period	5 years
Life Storage Spacemax LLC
Schedule of Equity Method Investments [Line Items]
Equity in earnings of unconsolidated real estate ventures - impairment (loss) on joint venture interests and gain on sale of joint venture interests			$ (13,883)

INVESTMENTS IN DEBT SECURITIES AND NOTES RECEIVABLE

9 Months Ended

Sep. 30, 2026

Investments, Debt and Equity Securities [Abstract]

INVESTMENTS IN DEBT SECURITIES AND NOTES RECEIVABLE

Investments in debt securities and notes receivable consist of the Company’s investment in mandatorily redeemable preferred stock of Jernigan Capital, Inc. (“JCAP”) in connection with JCAP’s acquisition by affiliates of NexPoint Advisors, L.P. (“NexPoint”) and receivables due to the Company under its bridge loan program. Information about these balances is as follows:


	September 30, 2026		December 31, 2025
Debt securities - preferred stock	$	300,000	$	300,000
Notes receivable - bridge loans, net	1,401,151		1,500,151

Dividends and interest receivable	6,375		6,375
	$	1,707,526	$	1,806,526

In November 2020, the Company invested $300,000 in the preferred stock of JCAP in connection with the acquisition of JCAP by NexPoint. This investment consisted of 200,000 Series A Preferred Shares valued at a total of $200,000, and 100,000 Series B Preferred Shares valued at a total of $100,000. In December 2022, the Company completed a modification with NexPoint Storage Partners (as successor in interest to JCAP) that exchanged the Series A and Series B Preferred Shares for 300,000 Series D Preferred Shares, valued at a total of $300,000. The Series D Preferred Shares are mandatorily redeemable after six years from the modification in December 2022, with two one-year extension options. NexPoint may redeem the Series D Preferred Shares at any time, subject to certain prepayment penalties. The Company accounts for the Series D Preferred Shares as a held to maturity debt security at amortized cost and evaluates whether the fair value is below the amortized cost basis at each reporting period. The Series D Preferred Shares have an initial dividend rate of 8.5%. If the investment is not retired after six years, the preferred dividends increase annually.

The Company offers bridge loan financing to third-party self-storage owners primarily for whom it manages properties. These notes receivable consist of mortgage loans receivable, which are collateralized by self-storage properties, and mezzanine loans receivable, which are secured by equity interest pledges. As of September 30, 2026, 82% of the notes held are mortgage receivables. The Company may sell a portion of the mortgage receivables. These notes receivable typically have a term of three years with two one-year extensions and have variable interest rates. During the nine months ended September 30, 2026, the Company sold a total principal amount of $30,414 of its mortgage bridge loans receivable to third parties for par, collected $326,448 of principal from payoffs and asset acquisitions, closed on $181,375 in initial loan draws, and recorded $13,910 of draws to fund interest payments.

The bridge loans typically have a loan to value ratio between 70% and 80% at origination. As of September 30, 2026, none of the notes receivable are in nonaccrual status, and any notes receivable where the monthly payments are delinquent are less than 150 days past due and immaterial. The allowance for potential credit losses is immaterial.

ACQUISITIONS AND DISPOSITIONS - Schedule of Held For Sale Activity (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2026 USD ($) store	Jun. 30, 2026 USD ($) store	Mar. 31, 2026 USD ($) store	Sep. 30, 2025 USD ($) store	Jun. 30, 2025 USD ($) store	Mar. 31, 2025 USD ($) store
Carrying Value of Assets Held for Sale
Asset held for sale at beginning	$ 28,280	$ 20,719	$ 27,140	$ 18,798	$ 28,238	$ 103,756
Assets held for sale, additions	13,255	7,561	0	175,289	0	8,019
Assets held for sale, disposals	(6,000)	0	(6,421)	0	(9,440)	(83,537)
Assets held for sale, removals	(7,561)
Asset held for sale at ending	27,974	28,280	20,719	194,087	18,798	28,238
(Gain) / Loss Recognized
(Gain) loss recognized at beginning	0	0	0	(34,897)	(35,761)	0
(Gain) loss recognized, additions	4,850	0	0	105,128	0	3,759
(Gain) loss recognized, disposals	971	0	0	0	864	(39,520)
(Gain) loss recognized, removals	0
(Gain) loss recognized at ending	$ 5,821	$ 0	$ 0	$ 70,231	$ (34,897)	$ (35,761)
Number of Stores
Number of stores at beginning \| store	6	4	5	4	5	13
Number of stores, additions \| store	1	2	0	25	0	3
Number of stores, disposals \| store	(1)	0	(1)	0	(1)	(11)
Number of stores, removals \| store	(2)
Number of stores at ending \| store	4	6	4	29	4	5

STOCKHOLDERS’ EQUITY (Details) $ / shares in Units, $ in Thousands			9 Months Ended	12 Months Ended
	Oct. 01, 2026 USD ($) $ / shares shares	Apr. 15, 2024 USD ($) sales_agent shares	Sep. 30, 2026 USD ($) $ / shares shares	Dec. 31, 2025 USD ($) $ / shares shares	Oct. 15, 2026 USD ($)	Nov. 13, 2023 USD ($)
Class of Stock [Line Items]
Share repurchase program, aggregate value						$ 500,000
Repurchase of common stock (in shares) \| shares			2,401,606	1,158,244
Average cost (dollars per share) \| $ / shares			$ 136.81	$ 129.10
Repurchase of common stock, net of commissions paid			$ 328,573	$ 149,525
Share repurchase program, remaining authorization value			$ 21,903
Subsequent Event
Class of Stock [Line Items]
Share repurchase program, aggregate value					$ 500,000
Repurchase of common stock (in shares) \| shares	164,724
Average cost (dollars per share) \| $ / shares	$ 132.45
Repurchase of common stock, net of commissions paid	$ 21,818
At the Market Equity Distribution Agreement
Class of Stock [Line Items]
Aggregate offering price of common shares		$ 800,000
Number of sales agents \| sales_agent		9
Shares issued (in shares) \| shares		0

DEBT - Schedule of Maturities of Notes Payable (Details) - Term Debt - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Debt Instrument [Line Items]
2026	$ 622,104
2027	991,484
2028	1,882,092
2029	1,763,489
2030	1,689,650
2031	1,777,347
2032	1,150,000
2033	800,000
2034	600,000
2035	900,000
Thereafter	21,200
Total	$ 12,197,366	$ 12,257,899

DERIVATIVES - Schedule of Balance Sheet Classification and Fair Value of Entity's Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Other assets	$ 1,059	$ 3,362
Other liabilities	$ 60	$ 2,538

INVESTMENTS IN DEBT SECURITIES AND NOTES RECEIVABLE - Additional Information (Details) $ in Thousands	1 Months Ended		9 Months Ended
	Dec. 31, 2022 USD ($) extension_option shares	Nov. 30, 2020 USD ($) shares	Sep. 30, 2026 USD ($) extension_option debt_security Rate	Sep. 30, 2025 USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Investment in debt securities		$ 300,000
Debt securities, term	6 years
Debt securities, extension option \| extension_option	2
Debt securities, extension term	1 year
Debt securities, period after which preferred dividends increase annually	6 years
Bridge loans, percent of notes held as mortgage receivables \| Rate			82.00%
Bridge loans, extension option \| extension_option			2
Bridge loans, extension term			1 year
Principal payments received			$ 306,187	$ 137,962
Issuance of notes receivable			$ 245,531	$ 512,377
Number of debt securities past due or nonaccrual status \| debt_security			0
Minimum
Schedule of Held-to-maturity Securities [Line Items]
Loan to value ratio			0.70
Maximum
Schedule of Held-to-maturity Securities [Line Items]
Loan to value ratio			0.80
Notes receivable - bridge loans, net
Schedule of Held-to-maturity Securities [Line Items]
Bridge loans, original maturities			3 years
Principal amount of notes sold			$ 30,414
Principal payments received			326,448
Issuance of notes receivable			181,375
Payment for draw on interest holdback			$ 13,910
JCAP Series A Preferred Stock
Schedule of Held-to-maturity Securities [Line Items]
Investment in debt securities		$ 200,000
Investment in debt securities (in shares) \| shares		200,000
JCAP Series B Preferred Stock
Schedule of Held-to-maturity Securities [Line Items]
Investment in debt securities		$ 100,000
Investment in debt securities (in shares) \| shares		100,000
JCAP Series D Preferred Stock
Schedule of Held-to-maturity Securities [Line Items]
Shares exchanged (in shares) \| shares	300,000
Shares exchanged, value	$ 300,000
Debt securities, dividend rate	8.50%

INVESTMENTS IN UNCONSOLIDATED REAL ESTATE ENTITIES

9 Months Ended

Sep. 30, 2026

Equity Method Investments and Joint Ventures [Abstract]

INVESTMENTS IN UNCONSOLIDATED REAL ESTATE ENTITIES

Investments in unconsolidated real estate entities and cash distributions in unconsolidated real estate ventures represent the Company’s interest in preferred stock of Strategic Storage Trust VI, Inc. and Strategic Storage Growth Trust III, Inc. (collectively, “Strategic Storage”), affiliates of SmartStop Self Storage REIT, Inc., and the Company’s noncontrolling interest in real estate joint ventures. The Company accounts for its investments in Strategic Storage preferred stock, which do not have a readily determinable fair value, at the transaction price less impairment, if any. The Company accounts for its investments in joint ventures using the equity method of accounting. The Company initially records these investments at cost and subsequently

adjusts for cash contributions, distributions and net equity in income or loss, which is allocated in accordance with the provisions of the applicable partnership or joint venture agreement. Equity in earnings and dividend income from these investments is included in the equity in earnings and dividend income from unconsolidated real estate entities on the Company’s condensed consolidated statements of operations.

In these joint ventures, the Company and the joint venture partner generally receive a preferred return on their invested capital. To the extent that cash or profits in excess of these preferred returns are generated through operations or capital transactions, the Company would receive a higher percentage of the excess cash or profits, as applicable, than its equity interest.

The Company separately reports investments with net equity less than zero in cash distributions in unconsolidated real estate ventures in the condensed consolidated balance sheets. The net equity of certain joint ventures is less than zero because distributions have exceeded the Company’s investment in and share of income from these joint ventures. This is generally the result of financing distributions, capital events or operating distributions that are usually greater than net income, as net income includes non-cash charges for depreciation and amortization while distributions do not.

Net investments in unconsolidated real estate entities and cash distributions in unconsolidated real estate ventures consist of the following:


	Number of Stores	Equity Ownership %	Excess Profit % (1)	September 30,		December 31,
				2026		2025
PRISA Self Storage LLC	85	4%	4%	$	8,428	$	8,736
HF1 Sovran HHF Storage Holdings LLC	37	49%	49%-59%	297,606		301,794
Storage Portfolio II JV LLC	36	10%	30%	(11,445)		(10,588)
Storage Portfolio IV JV LLC	32	10%	30%	45,608		46,310
Storage Portfolio I LLC	24	34%	49%	(45,204)		(44,537)
HF2 Sovran HHF Storage Holdings II LLC	22	49%	49%-59%	110,928		112,551
HF5 Life Storage-HIERS Storage LLC	17	20%	20%	23,860		24,580
HF6 191 V Life Storage Holdings LLC	17	20%	20%	7,470		9,525
VRS Self Storage, LLC	16	45%	54%	(19,252)		(18,576)
HF10 Life Storage HHF Wasatch Holdings LLC	16	20%	20%	17,373		18,082
Other unconsolidated real estate ventures (2)	106	10%-50%	10%-50%	284,122		295,205
Strategic Storage Growth Trust III, Inc. Preferred Stock (3)	n/a	n/a	n/a	100,000		100,000
Strategic Storage Trust VI, Inc. Preferred Stock (4)	n/a	n/a	n/a	150,000		150,000
Net Investments in and Cash distributions in unconsolidated real estate entities	408			$	969,494	$	993,082

Investments in unconsolidated real estate entities				$	1,045,395	$	1,066,783
Cash distributions in unconsolidated real estate ventures				(75,901)		(73,701)
Net Investments in and Cash distributions in unconsolidated real estate entities				$	969,494	$	993,082

(1) Includes pro-rata equity ownership share and promoted interest.

Cover - shares	9 Months Ended
Cover - shares	Sep. 30, 2026	Oct. 23, 2026
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2026
Document Transition Report	false
Entity File Number	001-32269
Entity Registrant Name	EXTRA SPACE STORAGE INC.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	20-1076777
Entity Address, Address Line One	2795 East Cottonwood Parkway, Suite 300
Entity Address, City or Town	Salt Lake City
Entity Address, State or Province	UT
Entity Address, Postal Zip Code	84121
City Area Code	801
Local Phone Number	365-4600
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	EXR
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		208,719,831
Amendment Flag	false
Document Fiscal Year Focus	2026
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001289490
Current Fiscal Year End Date	--12-31

EARNINGS PER COMMON SHARE - Schedule of Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Earnings Per Share [Abstract]
Net income attributable to common stockholders	$ 247,759	$ 165,998	$ 752,207	$ 686,604
Earnings and dividends allocated to participating securities	(460)	(430)	(1,354)	(1,295)
Net income for basic computations	247,299	165,568	750,853	685,309
Income allocated to noncontrolling interest - Preferred OP Units and OP Units	11,003	7,293	33,448	0
Net income for diluted computations	$ 258,302	$ 172,861	$ 784,301	$ 685,309
Weighted average common shares outstanding:
Average number of common shares outstanding - basic (in shares)	210,646,953	211,963,870	210,834,426	211,918,589
Common OP Units (in shares)	9,379,076	9,341,088	9,401,771	0
Average number of common shares outstanding - diluted (in shares)	220,026,029	221,304,958	220,236,197	211,918,589
Earnings per common share
Basic (in dollars per share)	$ 1.17	$ 0.78	$ 3.56	$ 3.23
Diluted (in dollars per share)	$ 1.17	$ 0.78	$ 3.56	$ 3.23

DERIVATIVES

9 Months Ended

Sep. 30, 2026

Derivative Instruments and Hedging Activities Disclosure [Abstract]

DERIVATIVES

The Company is exposed to certain risks arising from both its business operations and economic conditions. The Company principally manages its exposures to a wide variety of business and operational risks through management of its core business activities. The Company manages economic risks, including interest rate, liquidity and credit risk, primarily by managing the amount, sources and duration of its debt funding and the use of derivative financial instruments. Specifically, the Company enters into derivative financial instruments to manage exposures that arise from business activities that result in the receipt or payment of future known and uncertain cash amounts, the value of which are determined by interest rates. The Company’s derivative financial instruments are used to manage differences in the amount, timing and duration of the Company’s known or expected cash payments principally related to the Company’s borrowings.

Cash Flow Hedges of Interest Rate Risk

The Company’s objectives in using interest rate derivatives are to add stability to interest expense and to manage its exposure to interest rate movements. To accomplish these objectives, the Company primarily uses interest rate swaps as part of its interest rate risk management strategy. Interest rate swaps designated as cash flow hedges involve the receipt of variable amounts from a counterparty in exchange for the Company making fixed-rate payments over the life of the agreements without exchange of the underlying notional amount.

The effective portion of changes in the fair value of derivatives designated and that qualify as cash flow hedges is recorded in accumulated other comprehensive income (“OCI”) and is subsequently reclassified into earnings in the period that the hedged forecasted transaction affects earnings. A portion of these changes is excluded from accumulated other comprehensive income as it is allocated to noncontrolling interests. During the three and nine months ended September 30, 2026 and 2025, such derivatives were used to hedge the variable cash flows associated with existing variable-rate debt. In the next 12 months, the Company estimates that $627 will be reclassified as a decrease to interest expense. As of September 30, 2026, the Company held five active derivative financial instruments, which had a total current notional amount of $777,000.

Fair Values of Derivative Instruments

The table below presents the fair values of the Company’s derivative financial instruments as well as their classification on the condensed consolidated balance sheets:


	Asset / Liability Derivatives
Derivatives designated as hedging instruments:	September 30, 2026		December 31, 2025
Other assets	$	1,059	$	3,362
Other liabilities	$	60	$	2,538

Effect of Derivative Instruments


	Gain (loss) recognized in OCI for the Three Months Ended September 30,				Location of amounts reclassified from OCI into income	Gain (loss) reclassified from OCI for the Three Months Ended September 30,
Type	2026		2025			2026		2025
Swap Agreements	$	329	$	874	Interest expense	$	234	$	2,822
	Gain (loss) recognized in OCI for the Nine Months Ended September 30,				Location of amounts reclassified from OCI into income	Gain (loss) reclassified from OCI for the Nine Months Ended September 30,
Type	2026		2025			2026		2025
Swap Agreements	$	3,099	$	(2,572)	Interest expense	$	2,761	$	9,490

Credit-Risk-Related Contingent Features

The Company has agreements with some of its derivative counterparties that contain provisions pursuant to which the Company could be declared in default of its derivative obligations if the Company defaults on any of its indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender.

The Company also has an agreement with some of its derivative counterparties that incorporates the loan covenant provisions of the Company’s indebtedness with a lender affiliate of the derivative counterparty. Failure to comply with the loan covenant provisions would result in the Company being in default on any derivative instrument obligations covered by the agreement.

As of September 30, 2026, the Company had not posted any collateral related to these agreements. If the Company had breached any of these provisions as of September 30, 2026, it could have been required to cash settle its obligations under these agreements at their termination value.

INVESTMENTS IN DEBT SECURITIES AND NOTES RECEIVABLE - Schedule of Investments in Debt Securities and Bridge Loans Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Schedule of Held-to-maturity Securities [Line Items]
Dividends and interest receivable	$ 6,375	$ 6,375
Investments in debt securities and notes receivable	1,707,526	1,806,526
Notes receivable - bridge loans, net
Schedule of Held-to-maturity Securities [Line Items]
Notes receivable - bridge loans, net	1,401,151	1,500,151
JCAP Series A Preferred Stock
Schedule of Held-to-maturity Securities [Line Items]
Debt securities - preferred stock	$ 300,000	$ 300,000

FAIR VALUE DISCLOSURES - Schedule of Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Fair Value
Fair Value of Financial Instruments [Line Items]
Note receivable from Common Operating Partnership unit holder	$ 0	$ 51,122
Fixed rate notes receivable	81,917	62,307
Fixed rate debt	10,277,727	10,967,415
Carrying Value
Fair Value of Financial Instruments [Line Items]
Note receivable from Common Operating Partnership unit holder	0	50,000
Fixed rate notes receivable	83,690	62,207
Fixed rate debt	$ 10,772,847	$ 10,966,511

REAL ESTATE ASSETS (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Real Estate [Abstract]
Land	$ 5,155,953	$ 5,135,719
Buildings, improvements and other intangibles	23,627,672	23,234,033
Right of use assets - finance lease	136,608	141,194
Intangible assets - tenant relationships	335,955	334,669
Intangible lease rights	37,779	37,771
Gross operating real estate assets	29,293,967	28,883,386
Less: accumulated depreciation and amortization	(4,503,974)	(3,982,125)
Net operating real estate assets	24,789,993	24,901,261
Real estate under development/redevelopment	110,154	103,089
Real estate assets, net	$ 24,900,147	$ 25,004,350

STOCKHOLDERS’ EQUITY	9 Months Ended
STOCKHOLDERS’ EQUITY	Sep. 30, 2026
Stockholders' Equity Note [Abstract]
STOCKHOLDERS’ EQUITY	STOCKHOLDERS’ EQUITY On April 15, 2024, the Company filed its $800,000 “at the market” equity program with the SEC using a shelf registration statement on Form S-3, and entered into an equity distribution agreement with nine sales agents. No shares have been sold under the current “at the market” equity program. On November 13, 2023, the Company’s board of directors authorized a share repurchase program allowing for the repurchase of shares with an aggregate value up to $500,000. During the year ended December 31, 2025, the Company repurchased 1,158,244 shares at an average price of $129.10 per share, paying a total of $149,525. During the nine months ended September 30, 2026, the Company repurchased 2,401,606 shares at an average price of $136.81 per share, paying a total of $328,573. As of September 30, 2026, the Company had remaining authorization to repurchase shares with an aggregate value up to $21,903. On October 1, 2026, subsequent to the end of the quarter, the Company utilized the remaining authorization available under the existing repurchase program, repurchasing 164,724 shares at an average price of $132.45 per share, paying a total of $21,818. On October 15, 2026, the Company’s board of directors authorized a new share repurchase program allowing for the repurchase of shares with an aggregate value up to $500,000.

DEBT - Schedule of Components of Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Secured notes payable
Debt Instrument [Line Items]
Total	$ 1,072,366	$ 1,082,899
Less: Unamortized debt issuance costs	(60,252)	(63,506)
Unsecured term loans
Debt Instrument [Line Items]
Total	1,500,000	1,500,000
Unsecured senior notes
Debt Instrument [Line Items]
Total	9,625,000	9,675,000
Less: Discount on unsecured senior notes, net	(155,310)	(187,742)
Unsecured senior notes \| Life Storage, Inc
Debt Instrument [Line Items]
Unamortized cash discount	293,134
Term Debt
Debt Instrument [Line Items]
Total	12,197,366	12,257,899
Total	11,981,804	$ 12,006,651
Bonds
Debt Instrument [Line Items]
Unamortized debt premium	13,853
Assumed Debt From Merger
Debt Instrument [Line Items]
Unamortized cash discount	$ 15,018

DEBT - Additional Information (Details) - USD ($)	9 Months Ended
DEBT - Additional Information (Details) - USD ($)	Sep. 30, 2026	Dec. 31, 2025
Debt Instrument [Line Items]
Commercial paper	$ 1,424,000,000	$ 1,224,000,000
Fixed rate debt	4.30%
Variable rate debt	4.80%
Weighted average interest rate	4.40%
Commercial paper
Debt Instrument [Line Items]
Revolving credit facility, maximum borrowing capacity	$ 1,000,000,000
Debt instrument, term	3 months
Commercial paper	$ 850,000,000
Weighted-average maturity term	19 days
Commercial paper \| Maximum
Debt Instrument [Line Items]
Debt instrument, term	397 days
Fourth Amended and Restated Credit Agreement
Debt Instrument [Line Items]
Fixed rate to total debt percentage	79.60%

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Assets:
Real estate assets, net	$ 24,900,147	$ 25,004,350
Real estate assets - operating lease right-of-use assets	727,627	732,176
Investments in unconsolidated real estate entities	1,045,395	1,066,783
Investments in debt securities and notes receivable	1,707,526	1,806,526
Cash and cash equivalents	114,824	138,920
Other assets, net	467,600	515,291
Total assets	28,963,119	29,264,046
Liabilities, Noncontrolling Interests and Equity:
Secured notes payable, net	1,070,062	1,079,565
Unsecured term loans, net	1,495,717	1,494,659
Unsecured senior notes, net	9,416,025	9,432,427
Revolving lines of credit and commercial paper	1,424,000	1,224,000
Operating lease liabilities	765,718	761,106
Cash distributions in unconsolidated real estate ventures	75,901	73,701
Accounts payable and accrued expenses	458,777	357,583
Other liabilities	494,835	516,969
Total liabilities	15,201,035	14,940,010
Commitments and contingencies
Extra Space Storage Inc. stockholders’ equity:
Preferred stock, $0.01 par value, 50,000,000 shares authorized, no shares issued or outstanding	0	0
Common stock, $0.01 par value, 500,000,000 shares authorized, 208,884,163 and 211,155,322 shares issued and outstanding at September 30, 2026 and December 31, 2025, respectively	2,089	2,112
Additional paid-in capital	14,895,156	14,880,646
Accumulated other comprehensive loss	(89)	(420)
Accumulated deficit	(2,050,907)	(1,449,172)
Total Extra Space Storage Inc. stockholders’ equity	12,846,249	13,433,166
Noncontrolling interest represented by Preferred Operating Partnership units	47,827	53,827
Noncontrolling interests in Operating Partnership, net and other noncontrolling interests	868,008	837,043
Total noncontrolling interests and equity	13,762,084	14,324,036
Total liabilities, noncontrolling interests and equity	$ 28,963,119	$ 29,264,046

NONCONTROLLING INTEREST REPRESENTED BY PREFERRED OPERATING PARTNERSHIP UNITS - Schedule of Preferred of OP Units (Details) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Noncontrolling Interest [Line Items]
Noncontrolling interest represented by Preferred Operating Partnership units	$ 47,827	$ 53,827
Series B Units
Noncontrolling Interest [Line Items]
Noncontrolling interest represented by Preferred Operating Partnership units	33,567	33,567
Series D Units
Noncontrolling Interest [Line Items]
Noncontrolling interest represented by Preferred Operating Partnership units	$ 14,260	$ 20,260

Condensed Consolidated Statements of Noncontrolling Interests and Equity - USD ($) $ in Thousands	Total	Redemption Of Units For Common Stock	Redemption Of Units For Cash	Preferred Operating Partnership	Preferred Operating Partnership Redemption Of Units For Common Stock	Preferred Operating Partnership Redemption Of Units For Cash	Operating Partnership	Operating Partnership Redemption Of Units For Common Stock	Operating Partnership Redemption Of Units For Cash	Other	Common Stock	Common Stock Redemption Of Units For Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Redemption Of Units For Common Stock	Additional Paid-in Capital Redemption Of Units For Cash	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Dec. 31, 2024	$ 14,859,362			$ 76,092			$ 823,898			$ 11,837	$ 2,120		$ 14,831,946			$ 12,806	$ (899,337)
Beginning balance (in shares) at Dec. 31, 2024											211,995,510
Increase (Decrease) in Stockholders' Equity
Issuance of common stock for share based compensation and taxes paid upon net settlement (in shares)											134,656
Issuance of common stock for share based compensation and taxes paid upon net settlement	14,374										$ 1		14,373
Redemption of Operating Partnership units for stock		$ 0			$ (22,265)			$ (3,953)				$ 3		$ 26,215
Redemption of Operating Partnership units for stock (in shares)												185,808
Redemption of Operating Partnership units for cash			$ (1,453)						$ (924)						$ (529)
Issuance of Operating Partnership units in conjunction with acquisitions	5,878						5,878
Repurchase of common stock (in shares)											(68,585)
Repurchase of common stock	(8,615)										$ (1)						(8,614)
Purchase of remaining equity interest in existing consolidated joint venture	(5,994)									(1,426)			(4,568)
Noncontrolling interest in consolidated joint ventures	3,099									3,099
Net income	721,674			2,171			32,895			4							686,604
Other comprehensive income (loss)	(12,035)						(567)									(11,468)
Distributions to Operating Partnership units and other noncontrolling interests	(47,948)			(2,171)			(45,631)			(146)
Dividends paid on common stock	(1,031,930)																(1,031,930)
Ending balance at Sep. 30, 2025	14,496,412			53,827			811,596			13,368	$ 2,123		14,867,437			1,338	(1,253,277)
Ending balance (in shares) at Sep. 30, 2025											212,247,389
Beginning balance at Dec. 31, 2024	$ 14,859,362			76,092			823,898			11,837	$ 2,120		14,831,946			12,806	(899,337)
Beginning balance (in shares) at Dec. 31, 2024											211,995,510
Increase (Decrease) in Stockholders' Equity
Repurchase of common stock (in shares)	(1,158,244)
Ending balance at Dec. 31, 2025	$ 14,324,036			53,827			822,869			14,174	$ 2,112		14,880,646			(420)	(1,449,172)
Ending balance (in shares) at Dec. 31, 2025	211,155,322										211,155,322
Beginning balance at Jun. 30, 2025	$ 14,677,089			53,827			820,254			12,166	$ 2,123		14,860,946			3,203	(1,075,430)
Beginning balance (in shares) at Jun. 30, 2025											212,252,547
Increase (Decrease) in Stockholders' Equity
Issuance of common stock for share based compensation and taxes paid upon net settlement (in shares)											(5,158)
Issuance of common stock for share based compensation and taxes paid upon net settlement	6,929												6,929
Redemption of Operating Partnership units for cash			(1,174)						(736)						(438)
Noncontrolling interest in consolidated joint ventures	1,241									1,241
Net income	174,033			724			7,293			18							165,998
Other comprehensive income (loss)	(1,949)						(84)									(1,865)
Distributions to Operating Partnership units and other noncontrolling interests	(15,912)			(724)			(15,131)			(57)
Dividends paid on common stock	(343,845)																(343,845)
Ending balance at Sep. 30, 2025	14,496,412			53,827			811,596			13,368	$ 2,123		14,867,437			1,338	(1,253,277)
Ending balance (in shares) at Sep. 30, 2025											212,247,389
Beginning balance at Dec. 31, 2025	$ 14,324,036			53,827			822,869			14,174	$ 2,112		14,880,646			(420)	(1,449,172)
Beginning balance (in shares) at Dec. 31, 2025	211,155,322										211,155,322
Increase (Decrease) in Stockholders' Equity
Issuance of common stock for share based compensation and taxes paid upon net settlement (in shares)											130,447
Issuance of common stock for share based compensation and taxes paid upon net settlement	$ 17,570										$ 1		17,569
Redemption of Operating Partnership units for cash			$ (13,655)			$ (6,000)			$ (4,984)						$ (2,671)
Repayment of receivable with Operating Partnership units pledged as collateral	$ 50,000						50,000
Repurchase of common stock (in shares)	(2,401,606)										(2,401,606)
Repurchase of common stock	$ (328,622)										$ (24)						(328,598)
Purchase of remaining equity interest in existing consolidated joint venture	(5,304)									(4,916)			(388)
Noncontrolling interest in consolidated joint ventures	2,659									2,659
Net income	787,744			2,021			33,448			68							752,207
Other comprehensive income (loss)	338						7									331
Distributions to Operating Partnership units and other noncontrolling interests	(47,338)			(2,021)			(45,666)			349
Dividends paid on common stock	(1,025,344)																(1,025,344)
Ending balance at Sep. 30, 2026	$ 13,762,084			47,827			855,674			12,334	$ 2,089		14,895,156			(89)	(2,050,907)
Ending balance (in shares) at Sep. 30, 2026	208,884,163										208,884,163
Beginning balance at Jun. 30, 2026	$ 14,177,334			47,827			859,864			11,748	$ 2,113		14,886,836			(181)	(1,630,873)
Beginning balance (in shares) at Jun. 30, 2026											211,273,076
Increase (Decrease) in Stockholders' Equity
Issuance of common stock for share based compensation and taxes paid upon net settlement (in shares)											1,584
Issuance of common stock for share based compensation and taxes paid upon net settlement	8,320												8,320
Repurchase of common stock (in shares)											(2,390,497)
Repurchase of common stock	(327,179)										$ (24)						(327,155)
Noncontrolling interest in consolidated joint ventures	624									624
Net income	259,445			674			11,002			10							247,759
Other comprehensive income (loss)	94						2									92
Distributions to Operating Partnership units and other noncontrolling interests	(15,916)			(674)			(15,194)			(48)
Dividends paid on common stock	(340,638)																(340,638)
Ending balance at Sep. 30, 2026	$ 13,762,084			$ 47,827			$ 855,674			$ 12,334	$ 2,089		$ 14,895,156			$ (89)	$ (2,050,907)
Ending balance (in shares) at Sep. 30, 2026	208,884,163										208,884,163

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2026	Dec. 31, 2025
Statement of Financial Position [Abstract]
Preferred stock, par value (dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	50,000,000	50,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	500,000,000	500,000,000
Common stock, issued (in shares)	208,884,163	211,155,322
Common stock, outstanding (in shares)	208,884,163	211,155,322

BASIS OF PRESENTATION (Policies)	9 Months Ended
BASIS OF PRESENTATION (Policies)	Sep. 30, 2026
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements of the Company are presented on the accrual basis of accounting in accordance with U.S. generally accepted accounting principles (“GAAP”) for interim financial information, and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they may not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (including normal recurring accruals) considered necessary for a fair presentation have been included. Operating results for the three and nine months ended September 30, 2026 are not necessarily indicative of results that may be expected for the year ending December 31, 2026. The condensed consolidated balance sheet as of December 31, 2025 has been derived from the Company’s audited financial statements as of that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. For further information refer to the consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, as filed with the Securities and Exchange Commission (the “SEC”).
Recently Issued Accounting Standards	Recently Issued Accounting Standards In November 2024, the Financial Accounting Standards Board (the “FASB”) issued ASU No. 2024-03 – “Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40)”. The guidance requires the disclosure of additional information related to certain costs and expenses, including amounts of inventory purchases, employee compensation, and depreciation and amortization included in each income statement line item. For any remaining items within each relevant expense caption, entities must provide a qualitative description of the nature of those expenses. The guidance also requires disclosure of the total amount of selling expenses and the entity’s definition of selling expenses. The guidance is effective for annual periods beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027; therefore, compliance with this ASU will be required beginning with the Company’s Annual Report on Form 10-K for the year ending December 31, 2027. The guidance may be applied prospectively or retrospectively, and early adoption is permitted. Although the adoption is not expected to have a significant impact on the Company's financial statements, it is expected to result in incremental disclosures within the notes to the financial statements.

DERIVATIVES - Additional Information (Details) $ in Thousands	Sep. 30, 2026 USD ($) derivative
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Amount reclassified as a decrease to interest income	$ (627)
Number of derivative financial instruments \| derivative	5
Combined notional amount	$ 777,000