Acquisition of real estate assets Payments to Acquire Real Estate Document Type Document Type Receivable Type [Axis] Receivable Type [Axis] Schedule of investments in unconsolidated real estate ventures Schedule Of Real Estate Joint Ventures [Table Text Block] Tabular disclosure of information related to real estate joint ventures. Redemption of Operating Partnership units for stock (in shares) Stock Issued During Period, Shares, Conversion of Units Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes Amortization of discount Amortization of Debt Discount (Premium) Notes Receivable-Bridge Loans Bridge Loan [Member] Other assets - Cash flow hedge swap agreements Interest Rate Cash Flow Hedge Asset at Fair Value Noncontrolling Interest [Table] Noncontrolling Interest [Table] Segments [Axis] Segments [Axis] Note receivable interest rate Notes Receivable Stated Interest Rate Represents the stated interest rate of notes receivable. Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Buyback of common stock, net of offering costs (in shares) Repurchase of common stock (in shares) Stock Repurchased During Period, Shares Statistical Measurement [Domain] Statistical Measurement [Domain] Liabilities, Noncontrolling Interests and Equity: Liabilities and Equity [Abstract] Number of Stores Equity Method Investment, Number Of Properties Equity Method Investment, Number Of Properties Distributions to Operating Partnership units held by noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Derivatives Derivative Instruments and Hedging Activities Disclosure [Text Block] Security Exchange Name Security Exchange Name Income from operations Net operating income: Operating Income (Loss) Noncontrolling Interest Represented by Preferred Operating Partnership Units Noncontrolling Interest in Operating Partnership and Other Noncontrolling Interests Noncontrolling Interest Disclosure [Text Block] Storage Portfolio II JV LLC Storage Portfolio II JV LLC [Member] Storage Portfolio II JV LLC [Member] Investment in debt securities (in shares) Debt Securities, Held To Maturity, Number Of Shares Debt Securities, Held To Maturity, Number Of Shares Commitments and contingencies Commitments and Contingencies Repurchase of common stock Payments for Repurchase of Common Stock Assets: Assets [Abstract] Investment, Name [Axis] Investment, Name [Axis] Noncontrolling Interest - Preferred Operating Partnership Preferred Operating Partnership [Member] Preferred Operating Partnership [Member] Accounting Policies [Abstract] Accounting Policies [Abstract] Number of operating stores held-for-sale Number Of Operating Stores Held For Sale Number Of Operating Stores Held For Sale Entity Address, State or Province Entity Address, State or Province Other Commitments [Table] Other Commitments [Table] Fair Value of Financial Instruments [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Accumulated deficit Retained Earnings (Accumulated Deficit) Real estate assets - operating lease right-of-use assets Operating Lease, Right-of-Use Asset Earnings and dividends allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Property rental Lease Income Noncontrolling Interests and Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Earnings and dividends allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Basic JCAP Series B Preferred Stock JCAP Series B Preferred Stock [Member] JCAP Series B Preferred Stock Preferred stock, $0.01 par value, 50,000,000 shares authorized, no shares issued or outstanding Preferred Stock, Value, Issued Investment in unconsolidated real estate entities Payments to Acquire Equity Method Investments Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Common stock, par value (dollars per share) Common Stock, Par or Stated Value Per Share ESS-CA TIVS JV LP ESS-CA TIVS JV LP [Member] ESS-CA TIVS JV LP Deferred financing costs Payments of Financing Costs Loan to affiliates Origination of Notes Receivable from Related Parties Net income allocated to Preferred Operating Partnership noncontrolling interests Noncontrolling Interest in Net Income (Loss) Preferred Unit Holders, Redeemable Net Liabilities/ (Assets) Assumed Real Estate Property Acquisition, Increase Assets Acquired And Liabilities Assumed, Net The net value of assets transferred (liabilities assumed) in connection with the acquisition of real estate operating property. Management fees and other income Management fees and other income Revenue from Contract with Customer, Excluding Assessed Tax Measurement Frequency [Domain] Measurement Frequency [Domain] At the Market Equity Distribution Agreement At The Market Equity Distribution Agreement [Member] At The Market Equity Distribution Agreement [Member] Series D Units Series D Units [Member] Series D Units [Member] Number of units issued (in shares) Noncash or Part Noncash Acquisition, Noncash Financial or Equity Instrument Consideration, Shares Issued Aggregate offering price of common shares Aggregate Offering Price Of Common Share Aggregate offering price of common share. Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Statement [Line Items] Statement [Line Items] Schedule of Antidilutive Shares Excluded from Computation of Earnings Per Share Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Class of Stock [Domain] Class of Stock [Domain] Gain on real estate transactions Gains (Losses) On Real Estate Transactions And Earn Out From Prior Acquisition And Sale Of Other Assets Gains losses on real estate transactions and earn out from prior acquisition and sales of other assets Earnings per common share Earnings Per Share, Basic and Diluted [Abstract] Issuance and purchase of notes receivable Payments for issuance/purchase of notes receivable Payments to Acquire Notes Receivable Statement [Table] Statement [Table] Statistical Measurement [Axis] Statistical Measurement [Axis] Non-cash lease expense Operating Lease, Right-of-Use Asset, Amortization Expense SmartStop Self Storage REIT, Inc. Preferred Stock SmartStop Self Storage REIT Inc Series A Convertible Preferred Stock [Member] SmartStop Self Storage REIT Inc Series A Convertible Preferred Stock [Member] Preferred stock, issued (in shares) Preferred Stock, Shares Issued Redemption of Preferred Operating Partnership units for common stock Redemption Of Preferred Operating Partnership Units For Common Stock [Abstract] Redemption Of Preferred Operating Partnership Units For Common Stock Gain (loss) reclassified from OCI Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax Entity Small Business Entity Small Business Debt securities, term Debt Securities Held To Maturity, Term Debt Securities Held To Maturity, Term Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Shares issued (in shares) Sale of Stock, Number of Shares Issued in Transaction Investment in debt securities Payments to Acquire Held-to-maturity Securities Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Proceeds from the sale of common stock, net of offering costs Proceeds from Issuance of Common Stock Property operations Cost of Revenue Debt Instrument, Redemption, Period One Debt Instrument, Redemption, Period One [Member] Number of derivative financial instruments Derivative, Number of Instruments Held Amendment Flag Amendment Flag Schedule of Computation of Earnings Per Common Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Revolving lines of credit Long-term Line of Credit Restricted stock grants cancelled (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Forfeited Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Distributions to noncontrolling interests Payments of Ordinary Dividends, Noncontrolling Interest Excess Profit % Unconsolidated Joint Ventures Excess Profit Participation Percentage The percentage of excess profit participation in unconsolidated joint ventures. Entity Central Index Key Entity Central Index Key Shares related to the Notes included in the computation for diluted earnings per share (in shares) Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities Measurement Frequency [Axis] Measurement Frequency [Axis] Investment in unconsolidated real estate ventures received on sale of stores to joint venture Non Cash Investment In Joint Ventures [Abstract] Non Cash Investment In Joint Ventures Derivative Instrument [Axis] Derivative Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Income allocated to noncontrolling interest - Preferred Operating Partnership Units and Operating Partnership Units Net Income Loss Attributable To Noncontrolling Interest In Operating Partnership Net Income Loss Attributable To Noncontrolling Interest In Operating Partnership Schedule of Fair Value of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Debt Instrument, Redemption, Period Three Debt Instrument, Redemption, Period Three [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Fixed priority return on preferred OP units, stated return rate Noncontrolling Interest In Preferred Operating Partnership Units Fixed Priority Return Stated Rate Of Return Represents the fixed priority return, as a percent, of preferred operating partnership units attributable to noncontrolling preferred unit holders on which the fixed priority return is granted. Note receivable interest rate Financing Receivable, Stated Interest Rate Financing Receivable, Stated Interest Rate Accounts payable and accrued expenses Capital Expenditures Incurred but Not yet Paid Acquisitions of real estate assets Noncash Or Part Noncash Acquisition Net Real Estate Assets Acquired [Abstract] Noncash Or Part Noncash Acquisition Net Real Estate Assets Acquired [Abstract] Joint Venture 1 Joint Venture One [Member] Joint Venture One [Member] Schedule of Operating Properties Acquired Schedule Of Asset Acquisitions [Table Text Block] Schedule of Asset Acquisitions [Table Text Block] Segments [Domain] Segments [Domain] Establishment of finance lease assets and lease liabilities Noncash Right-Of-Use Assets And Finance Lease Liabilities [Abstract] Noncash Right-Of-Use Assets And Finance Lease Liabilities Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Preferred Operating Partnership units Conversion of Stock, Amount Converted Operating Partnership Holders of A Units Holders Of Series A Preferred Operating Partnership Units [Member] Holders Of Series A Preferred Operating Partnership Units [Member] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Other Commitments [Line Items] Other Commitments [Line Items] JCAP Series A Preferred Stock JCAP Series A Preferred Stock [Member] JCAP Series A Preferred Stock Estimated amount of unrealized gains (losses) expected to be reclassified as interest expense in next fiscal year Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Combined notional amount Derivative, Notional Amount OP Units redeemed for common stock (in units) Noncontrolling Interest, Operating Partnership Units Redeemed For Common Stock Noncontrolling Interest, Operating Partnership Units Redeemed For Common Stock Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] GFN JV, LLC GFN JV, LLC [Member] GFN JV, LLC [Member] Investments in Unconsolidated Real Estate Entities Equity Method Investments and Joint Ventures Disclosure [Text Block] Other liabilities Other Liabilities Segment Information Segment Reporting Disclosure [Text Block] Repurchase of exchangeable senior notes with common stock (in shares) Issuance Of Common Stock For Repayment Of Senior Debt, Shares Issuance Of Common Stock For Repayment Of Senior Debt, Shares Issuance of common stock, net of offering costs Stock Issued During Period, Value, New Issues Total assets Assets Loans and notes to affiliates Due from Related Parties, Noncurrent Total interest expense recognized Interest Expense, Debt Redemption of Operating Partnership units held by noncontrolling interests for common stock Redemption Of Operating Partnership Units Held By Noncontrolling Interests For Common Stock [Abstract] Redemption Of Operating Partnership Units Held By Noncontrolling Interests For Common Stock [Abstract] Title of 12(b) Security Title of 12(b) Security Common stock and paid-in capital Redemption Of Operating Partnership Units Held By Noncontrolling Interest Including Additional Paid In Capital Redemption Of Operating Partnership Units Held By Noncontrolling Interest Including Additional Paid In Capital Other minority owned stores Other Minority Owned Properties [Member] Other Minority Owned Properties [Member] Investments, Debt and Equity Securities [Abstract] Debt securities, extension term Debt Securities Held To Maturity, Extension Term Debt Securities Held To Maturity, Extension Term Interest expense Interest Expense Net proceeds Sale of Stock, Consideration Received on Transaction Store Acquisitions and Dispositions Mergers, Acquisitions and Dispositions Disclosures [Text Block] Depreciation and amortization Depreciation and amortization expense Depreciation, Depletion and Amortization Fixed priority return on preferred OP units, amount Noncontrolling Interest In Preferred Operating Partnership Units Fixed Priority Return Amount Represents the carrying amount of preferred operating partnership units attributable to noncontrolling preferred unit holders on which the fixed priority return is granted. Ownership interest held by joint venture partner Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Period used as a denomination to determine the average closing price of common stock Average Closing Market Price Measurement Period Represents the period over which the average market closing price is measured. Total liabilities Liabilities Investment Type [Axis] Investment Type [Axis] Amortization period Debt Issuance Cost Amortization Period Debt Issuance Cost Amortization Period Redeemable Noncontrolling Interest Redeemable Noncontrolling Interest [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Earnings for basic computations Net Income (Loss) Available to Common Stockholders, Basic Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Gain (loss) recognized in OCI Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Real Estate [Abstract] Real Estate [Abstract] Liquidation value (in dollars per share) Noncontrolling Interest In Preferred Operating Partnership Units Liquidation Value Per Unit Represents the liquidation value per unit of preferred operating partnership units. Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Number of states in which operating storage facilities are located Number of States in which Entity Operates Preferred Units by Name [Axis] Preferred Units by Name [Axis] Cash dividends paid per common share (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Debt Instrument [Axis] Debt Instrument [Axis] Additional Paid-in Capital Additional Paid-in Capital [Member] Other assets, net Other Assets Operating Segments Operating Segments [Member] Noncontrolling interests in Operating Partnership, net and other noncontrolling interests Noncontrolling Interest in Operating Partnerships Class of Stock [Line Items] Class of Stock [Line Items] Purchase of equipment and fixtures Payments to Acquire Furniture and Fixtures Noncontrolling interest represented by Preferred Operating Partnership units, net Noncontrolling Interest in Preferred Unit Holders Gain on sale Gains (Losses) on Sales of Investment Real Estate Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Principal amount of notes sold Financing Receivable, Sale Redemption of Operating Partnership units for stock Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Common stock, outstanding (in shares) Common Stock, Shares, Outstanding VRS Self Storage, LLC VRS Self Storage LLC [Member] VRS Self Storage LLC [Member] Investment, preferred dividend rate Preferred Stock Investment, Dividend Rate Preferred Stock Investment, Dividend Rate Common stock, authorized (in shares) Common Stock, Shares Authorized Net proceeds from exercise of stock options Proceeds from Stock Options Exercised Schedule of Financial Information of Business Segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Series A Units Series A Units [Member] Series A Units [Member] Contractual interest Interest Expense, Debt, Excluding Amortization Fair Value Estimate of Fair Value Measurement [Member] Income Statement [Abstract] Income Statement [Abstract] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Repurchase of exchangeable senior notes Repayments of Senior Debt Alan Jathoo JV LLC Alan Jathoo JV LLC [Member] Alan Jathoo JV LLC [Member] Accrual of interest income added to principal of debt securities and notes receivable Noncash Interest Income Noncash Interest Income Investments in Debt Securities and Bridge Loans Receivable Schedule Of Investments In Debt Securities And Financing Receivables [Table Text Block] Schedule Of Investments In Debt Securities And Financing Receivables Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Noncontrolling interests in Operating Partnership Noncontrolling Interest, Decrease From Redemptions Of Operating Partnership Units Noncontrolling Interest, Decrease From Redemptions Of Operating Partnership Units Interest income Investment Income, Interest Bridge loans, extension term Financing Receivable, Extension Term Financing Receivable, Extension Term Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Comprehensive income attributable to common stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Average share price (in dollars per share) Average Share Price Per Share Average Share Price Per Share Fixed component of income allocated to noncontrolling interest - Preferred Operating Partnership (Series A Units) Income (Loss) Attributable to Noncontrolling Interest Fixed Component Represents the component of income or loss attributable to the noncontrolling interest as a result of fixed distributions paid to Preferred Operating unit holders. Underwriting fee percentage Percentage of Underwriting Fee Percentage of Underwriting Fee Preferred stock, par value (dollars per share) Preferred Stock, Par or Stated Value Per Share Exchangeable preferred operating partnership units settled in cash, minimum Preferred Operating Partnership Units Amount to be Settled in Cash Minimum Represents the minimum amount of convertible preferred operating partnership units which will be settled in cash upon conversion. Legal Entity [Axis] Legal Entity [Axis] City Area Code City Area Code Consolidation Items [Domain] Consolidation Items [Domain] Interest expense Interest Expense, Excluding Amortization Of Debt Discount (Premium) Interest Expense, Excluding Amortization Of Debt Discount (Premium) Document Period End Date Document Period End Date Equity in earnings and dividend income from unconsolidated real estate entities Income (Loss) from Equity Method Investments Share repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Net income Net income Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Income before equity in earnings and dividend income from unconsolidated real estate ventures and income tax expense Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Compensation expense related to stock-based awards Share-based Payment Arrangement, Noncash Expense Buyback of common stock, net of offering costs Stock Repurchased During Period, Value Entity [Domain] Entity [Domain] Tenant reinsurance Tenant Reinsurance Expense The expense in the period incurred with respect to the entity's tenant reinsurance program. Issuance of common stock in connection with share based compensation (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Cover page. Cover [Abstract] Accrued construction costs and capital expenditures Accrued Construction Costs And Capital Expenditures [Abstract] Accrued Construction Costs And Capital Expenditures [Abstract] Number of stores owned by franchisees and third parties Number Of Real Estate Properties Franchisees And Others The number of real estate properties owned by franchisees and other third parties as of the balance sheet date. Additional paid-in capital Redemption Of Operating Partnership Units For Common Stock Including Additional Paid In Capital Represents the value of Operating Partnership units redeemed for common stock including additional paid in capital. Real estate assets Real Estate Assets Transferred For Investment In Joint Venture Real Estate Assets Transferred For Investment In Joint Venture Establishment of operating lease right of use assets and lease liabilities Noncash Right-Of-Use Assets And Operating Lease Liabilities [Abstract] Noncash Right-Of-Use Assets And Operating Lease Liabilities [Abstract] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Restricted cash Restricted Cash and Cash Equivalents Total expenses Operating expenses: Costs and Expenses Equity Components [Axis] Equity Components [Axis] Change in fair value of interest rate swaps Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Preferred units outstanding (in shares) Preferred Units, Outstanding Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Joint Venture 2 Joint Venture Two [Member] Joint Venture Two [Member] Minimum Minimum [Member] Balance Sheet Location [Domain] Balance Sheet Location [Domain] PRISA Self Storage LLC Prisa Self Storage LLC [Member] Prisa Self Storage LLC [Member] Number of sales agents Number Of Sales Agents Number Of Sales Agents Real estate assets, net Real estate assets associated with finance lease Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] Schedule of information relating to gain (loss) recognized on swap agreements Derivative Instruments, Gain (Loss) [Table Text Block] Entity Interactive Data Current Entity Interactive Data Current Schedule of balance sheet classification and fair value of entity's derivative financial instruments Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Gain on real estate transactions Gains (Losses) On Real Estate Transactions, Net Of Impairment Of Real Estate Gains (Losses) On Real Estate Transactions, Net Of Impairment Of Real Estate Revenues: Revenues [Abstract] Fair Value Disclosures Fair Value Disclosures [Text Block] Stockholders' Equity Stockholders' Equity Note Disclosure [Text Block] Swap Agreements Interest Rate Swap [Member] Additional paid-in capital Additional Paid in Capital, Common Stock Entity Registrant Name Entity Registrant Name Derivative [Table] Derivative [Table] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Investments in unconsolidated real estate entities Real Estate Investments, Unconsolidated Real Estate and Other Joint Ventures Other liabilities Increase (Decrease) in Other Operating Liabilities PR EXR Self Storage, LLC PR EXR Self Storage, LLC [Member] PR EXR Self Storage, LLC [Member] Related debt issuance costs Debt Issuance Costs, Net Number of reportable segments Number of Reportable Segments Investment in unconsolidated real estate ventures Noncash Investment In Joint Venture Noncash Investment In Joint Venture Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Dividends paid on common stock Payments of Ordinary Dividends, Common Stock Effective interest rate on the liability component Debt Instrument, Interest Rate, Effective Percentage Consolidation Items [Axis] Consolidation Items [Axis] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Ownership interest held Noncontrolling Interest, Ownership Percentage by Parent Fixed priority return on preferred OP units, liquidation value Noncontrolling Interest In Preferred Operating Partnership Units Fixed Priority Return Redemption Value Represents the liquidation value of preferred operating partnership units attributable to noncontrolling preferred unit holders on which the fixed priority return is granted. Noncontrolling Interest [Abstract] Noncontrolling Interest [Abstract] Preferred OP Units Preferred Units, Preferred Partners' Capital Accounts Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Distributions from unconsolidated real estate ventures in excess of earnings Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Number of consolidated joint ventures Real Estate Consolidated Joint Ventures Number Represents the number of consolidated joint ventures as of the balance sheet date. Purchase of note receivable Financing Receivable, Purchase Acquisition of real estate assets Real Estate Additions, Portion Not Yet Paid Real Estate Additions, Portion Not Yet Paid Commitment to acquire stores with joint venture partners Commitment To Acquire Retail Space With Joint Venture Partners [Member] Commitment To Acquire Retail Space With Joint Venture Partners [Member] Sale of Stock [Axis] Sale of Stock [Axis] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Debt Instrument, Redemption, Period Two Debt Instrument, Redemption, Period Two [Member] Commitment to acquire stores Commitment To Acquire Retail Space [Member] Commitment To Acquire Retail Space [Member] Annual rate of return percentage Noncontrolling Interest In Preferred Operating Partnership Units Annual Rate Of Return Represents the annual rate of return of preferred operating partnership units. Document Transition Report Document Transition Report Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Summary of amount of interest cost recognized relating to contractual interest rates and amortization of discounts on liability components of notes Schedule Of Interest And Amortization Discount Cost [Table Text Block] Tabular disclosure of interest cost recognized and the amortization of the discount on the liability component of the convertible debt instrument. Proceeds from sale of real estate assets Proceeds from Sale of Real Estate Dividends paid on common stock (in dollars per share) Common Stock, Dividends, Per Share, Declared Principal amount of notes issued Debt Instrument, Face Amount Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Document Quarterly Report Document Quarterly Report Shares converted (in shares) Conversion of Stock, Shares Converted Bridge loans, extension option Financing Receivable, Extension Option Financing Receivable, Extension Option Debt Securities, Held-to-maturity [Table] Debt Securities, Held-to-maturity [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Preferred Units, Class [Domain] Preferred Units, Class [Domain] Supplemental schedule of noncash investing and financing activities: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Exchangeable Senior Notes 3.125% due 2035 (the 2015 Notes) Exchangeable Senior Notes Three Point One Two Five Percent Due Two Thousand And Thirty Five [Member] Exchangeable Senior Notes Three Point One Two Five Percent Due Two Thousand And Thirty Five [Member] Return of investment in unconsolidated real estate ventures Return Of Investment Real Estate Ventures Distributions that represent a return of original investment from real estate ventures. Other liabilities Other Liabilities [Member] Derivative Contract [Domain] Derivative Contract [Domain] Proceeds from sale of real estate assets Proceeds from Sale of Real Estate Held-for-investment Diluted (in shares) Average number of common shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Value of units issued Real Estate Property Asset Acquisition, Consideration Transferred, Equity Interest Issued Or Issuable Real Estate Property Asset Acquisition, Consideration Transferred, Equity Interest Issued Or Issuable Basic (in dollars per share) Earnings Per Share, Basic Consideration to be paid on redemption of common OP units Operating Partnership Units Redemption Amount Represents the amount the entity would have paid in cash to redeem the operating partnership units. Entity File Number Entity File Number Storage Portfolio I LLC Storage Portfolio I LLC [Member] Storage Portfolio I LLC [Member] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Number of stores sold Number Of Stores Sold Number Of Stores Sold Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Dividends paid on common stock Dividends, Common Stock Depreciation and amortization Other Depreciation and Amortization Balance Sheet Location [Axis] Balance Sheet Location [Axis] Common stock, $0.01 par value, 500,000,000 shares authorized, 133,692,662 and 131,357,961 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively Common Stock, Value, Issued Document Fiscal Year Focus Document Fiscal Year Focus Proceeds from notes payable and revolving lines of credit Proceeds from Issuance of Secured Debt Real estate assets, net Noncash Or Part Noncash Acquisition Net Real Estate Assets Acquired Represents the amount of real estate assets that an Entity acquires in a noncash (or part noncash) acquisition. Real estate assets refer to the lands, buildings and intangible assets (including those that are part of operations and those under development) of a real estate entity, net of accumulated depreciation and amortization. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. Storage Portfolio III JV LLC Storage Portfolio III JV LLC [Member] Storage Portfolio III JV LLC Entity Current Reporting Status Entity Current Reporting Status Average sales price (in dollars per share) Sale of Stock, Price Per Share Receivable [Domain] Receivable [Domain] Development and redevelopment of real estate assets Payments to Develop Real Estate Assets Total comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Common stock, issued (in shares) Balance, beginning of period (in shares) Balance, end of period (in shares) Common Stock, Shares, Issued Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Repurchase of exchangeable senior notes with common stock Issuance Of Common Stock For Repayment Of Senior Debt, Value Issuance Of Common Stock For Repayment Of Senior Debt, Value Operating lease liabilities Operating Lease, Liability Period from date of issuance after which preferred OP units will become redeemable at the option of the holder Noncontrolling Interest In Preferred Operating Partnership Units Period From Date Of Issuance After Which Units Become Redeemable Represents the period from the date of issuance after which preferred units will become redeemable at the option of the holder. Segment Reporting [Abstract] Segment Reporting [Abstract] Debt securities, dividend rate Debt Securities Held To Maturity, Dividend Rate Debt Securities Held To Maturity, Dividend Rate Basis of Presentation Basis of Presentation and Significant Accounting Policies [Text Block] Debt Instrument [Line Items] Debt Instrument [Line Items] Other liabilities - Cash flow hedge swap agreements Derivative liability, fair value Interest Rate Cash Flow Hedge Liability at Fair Value Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Total Extra Space Storage Inc. stockholders' equity Stockholders' Equity Attributable to Parent Series B Units Series B Units [Member] Series B Units [Member] Organization Nature of Operations [Text Block] Total liabilities, noncontrolling interests and equity Liabilities and Equity Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Address, City or Town Entity Address, City or Town Portion at Fair Value Measurement [Member] [Default] Portion at Fair Value Measurement [Member] Notes payable, net Notes Payable Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Debt securities, period after which preferred dividends increase annually Debt Securities Held To Maturity, Period After Which Preferred Dividends Increase Annually Debt Securities Held To Maturity, Period After Which Preferred Dividends Increase Annually Other assets Other Assets [Member] Notes receivable Financing Receivable, after Allowance for Credit Loss General and administrative General and administrative expense General and Administrative Expense Financial Instrument [Axis] Financial Instrument [Axis] Maximum number of preferred OP units converted prior to the maturity date of the loan (in shares) Noncontrolling Interest Conversion Of Preferred Operating Partnership Units Before Maturity Of Loan Maximum Represents the maximum number of preferred operating partnership units that can be converted by noncontrolling holders of preferred units before maturity date of the loan. Anti-dilutive securities excluded from computation of earnings per common share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Equity Component [Domain] Equity Component [Domain] Real estate exchanged for interest in joint venture Exchange Of Real Estate For Interest In Joint Venture Exchange Of Real Estate For Interest In Joint Venture OP Units (in shares) Incremental Common Shares Attributable To Conversion Of Operating Partnership Units Shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible operating partnership units. Net income allocated to Operating Partnership and other noncontrolling interests Minority Interest In Net Income Loss Operating Partnerships And Other Amount of net income (loss) for the period allocated to noncontrolling partners of an operating partnership and others included in the entity's consolidated financial statements. Shares related to exchangeable senior notes and dilutive stock options (in shares) Incremental Common Shares Attributable To Share Based Payment Arrangements Stock Options Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements related to stock options. Entity Tax Identification Number Entity Tax Identification Number Net income attributable to common stockholders Net income attributable to common stockholders Net Income (Loss) Attributable to Parent Cash Paid Payments To Acquire Assets, Gross Payments To Acquire Assets, Gross Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Investment, Name [Domain] Investment, Name [Domain] Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Debt securities, extension option Debt Securities Held To Maturity, Extension Option Debt Securities Held To Maturity, Extension Option Current Fiscal Year End Date Current Fiscal Year End Date Ten day average closing stock price (in dollars per share) Common Stock Average Closing Market Price The average closing market price of the entity's common stock. Noncontrolling Interest - Other Other noncontrolling interests Non Controlling Interest Other [Member] Non Controlling Interest Other [Member] Less: comprehensive income attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Earnings Per Share [Abstract] Earnings Per Share [Abstract] Number of real estate properties to be acquired Number Of Real Estate Properties To Be Acquired Number Of Real Estate Properties To Be Acquired Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Debt securities Debt Securities, Held-to-maturity Non-cash interest expense related to amortization of discount on equity component of exchangeable senior notes Amortization Of Debt Discount (Premium), Equity Component Of Senior Notes Amortization Of Debt Discount (Premium), Equity Component Of Senior Notes Extra Space Storage Inc. stockholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Issuance of common stock in connection with share based compensation Stock Issued During Period, Value, Restricted Stock Award, Gross Cash distributions in unconsolidated real estate ventures Cash Distributions In Unconsolidated Real Estate Ventures Cash Distributions In Unconsolidated Real Estate Ventures Notes Receivable-Senior Mezzanine Loan Notes Receivable [Member] Number of operating storage facilities in which the entity has equity interests (in stores) Number of Real Estate Properties Net income for diluted computations Net Income (Loss) Available to Common Stockholders, Diluted Self-Storage Operations Self Storage Operations [Member] Self Storage Operations [Member] Supplemental schedule of cash flow information Supplemental Cash Flow Information [Abstract] OP units conversion ratio Shareholders' Equity, Units Conversion Ratio Shareholders' Equity, Units Conversion Ratio Entity Filer Category Entity Filer Category Common Stock Common Stock [Member] Exchangeable Senior Notes Exchangeable Senior Notes Disclosure [Text Block] The entire disclosure for information about the entity's exchangeable senior notes, including amounts of borrowings and about the underlying arrangements, including repayment terms, interest rates, collateral provided, and other matters important to the users of the financial statements. Fixed rate notes receivable Notes Receivable, Fair Value Disclosure Other Commitments [Axis] Other Commitments [Axis] Other Commitments [Domain] Other Commitments [Domain] Issuance of common stock, net of offering costs (in shares) Stock Issued During Period, Shares, New Issues Investments in Debt Securities and Notes Receivable Investments In Debt Securities And Financing Receivables [Text Block] Investments In Debt Securities And Financing Receivables Dividends Receivable Dividends Receivable Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Tenant Reinsurance Tenant Reinsurance [Member] Tenant Reinsurance [Member] Debt stated interest rate Debt Instrument, Interest Rate, Stated Percentage Finance lease liability Lease Obligation Incurred Total Consideration Paid Real Estate Property Asset Acquisition, Consideration Transferred Real Estate Property Asset Acquisition, Consideration Transferred Preferred OP units conversion ratio Noncontrolling Interest In Preferred Operating Partnership Units Conversion Ratio Represents the ratio for conversion of preferred operating partnership units into common OP units. Issuance of common stock upon the exercise of options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Net increase (decrease) in cash, cash equivalents, and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Unvested restricted stock awards included for treasury stock method (in shares) Incremental Common Shares Attributable to Dilutive Effect of Nonvested Shares with Forfeitable Dividends Noncontrolling interest in consolidated joint venture Noncontrolling Interest, Other Decrease Noncontrolling Interest, Other Decrease Stock Options Share-based Payment Arrangement, Option [Member] Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Basic (in shares) Average number of common shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Expenses: Costs and Expenses [Abstract] Ownership [Axis] Ownership [Axis] ESS Bristol Investments LLC ESS Bristol Investments, LLC [Member] ESS Bristol Investments, LLC [Member] Sale of Stock [Domain] Sale of Stock [Domain] Ownership [Domain] Ownership [Domain] Tenant reinsurance Direct Premiums Earned Carrying Value Reported Value Measurement [Member] Number of operating stores owned and/or managed Number Of Real Estate Properties Owned And Or Managed The number of real estate properties owned and/or managed as of the balance sheet date. ESS-NYFL JV LP ESS-NYFL JV LP [Member] ESS-NYFL JV LP [Member] Equity Ownership % Equity Method Investment, Ownership Percentage Interest paid Interest Paid, Excluding Capitalized Interest, Operating Activities Investments in debt securities and notes receivable Investments in debt securities and notes receivable Debt Securities, Held To Maturity And Financing Receivable, After Allowance For Credit Loss, And Interest Receivable Debt Securities, Held To Maturity And Financing Receivable, After Allowance For Credit Loss, And Interest Receivable Fair value - net liability position Derivative With Contingent Features, Fair Value Of Asset (Liability), Net Derivative With Contingent Features, Fair Value Of Asset (Liability), Net Other liabilities Establishment Of Finance Lease Liability Establishment Of Finance Lease Liability Total noncontrolling interests and equity Balance, beginning of period Balance, end of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Real estate assets - operating lease right-of-use assets Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Total revenues Revenues: Revenues Class of Stock [Axis] Class of Stock [Axis] Number of Stores Number Of Real Estate Properties Acquired Represents the number of real estate properties acquired. Income tax expense Income tax expense Income Tax Expense (Benefit) Income taxes paid Income Taxes Paid, Net Cash, cash equivalents, and restricted cash, beginning of the period Cash, cash equivalents, and restricted cash, end of the period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Loan receivable, reduction of noncontrolling interests Note Receivable, Reduction Of Noncontrolling Interests Note Receivable, Reduction Of Noncontrolling Interests Extra Space Northern Properties Six LLC Extra Space Northern Properties Six LLC [Member] Extra Space Northern Properties Six LLC [Member] Diluted (in dollars per share) Earnings Per Share, Diluted WICNN JV LLC WICNN JV LLC [Member] WICNN JV LLC [Member] Investment balance Investment In Unconsolidated Real Estate Entities, Net Of Distributions Investment In Unconsolidated Real Estate Entities, Net Of Distributions Local Phone Number Local Phone Number Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Number of operating stores owned Number Of Operating Stores Owned Number Of Operating Stores Owned Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Derivative [Line Items] Derivative [Line Items] Proceeds from sale of notes receivable Proceeds from Sale of Notes Receivable Entity Address, Address Line One Entity Address, Address Line One Notes receivable from Preferred and Common Operating Partnership unit holders Due From Related Parties Fair Value Disclosure Fair value of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due after one year (or one business cycle). Other assets Increase (Decrease) in Other Operating Assets Entity Emerging Growth Company Entity Emerging Growth Company Issuance of common stock upon the exercise of options Stock Issued During Period, Value, Stock Options Exercised Fixed liquidation value Noncontrolling Interest In Preferred Operating Partnership Units Fixed Liquidation Value Represents the fixed liquidation value of preferred operating partnership units. Investment redemption restriction period Preferred Stock Investment, Redemption Restriction Period Preferred Stock Investment, Redemption Restriction Period Award Type [Axis] Award Type [Axis] Maximum Maximum [Member] Amortization of deferred financing costs Amortization of Debt Issuance Costs Preferred stock, authorized (in shares) Preferred Stock, Shares Authorized Principal payments on notes payable and revolving lines of credit Repayments of Other Debt Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities Accumulated Deficit Retained Earnings [Member] Preferred stock, outstanding (in shares) Preferred Stock, Shares Outstanding Measurement Basis [Axis] Measurement Basis [Axis] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Net cash provided by (used in) investing activities Net Cash Provided by (Used in) Investing Activities Period after which preferred stock dividend is subject to increase Preferred Stock Investment, Period After Which Dividend Rate Is Subject To Increase Preferred Stock Investment, Period After Which Dividend Rate Is Subject To Increase Award Type [Domain] Award Type [Domain] Investments [Domain] Investments [Domain] Bridge loans, original maturities Financing Receivable, Term Financing Receivable, Term Contingent cash settlement value Derivative Instruments With Contingent Features, Contingent Cash Settlement Value Derivative Instruments With Contingent Features, Contingent Cash Settlement Value Trading Symbol Trading Symbol Weighted average number of shares Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Purchase price Other Commitment Noncontrolling Interest - Operating Partnership Common Operating Partnership [Member] Common Operating Partnership [Member] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Preferred Units (in shares) Incremental Common Shares Attributable to Exchangeable Preferred Operating Partnership Units Shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of exchangeable preferred operating partnership units. Earnings Per Common Share Earnings Per Share [Text Block] Fixed rate notes payable Notes Payable, Fair Value Disclosure Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Operating lease liabilities Establishment Of Operating Lease Liability Establishment Of Operating Lease Liability Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Entity Shell Company Entity Shell Company Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Series C Units Series C Units [Member] Series C Units [Member] Recurring Basis Fair Value, Recurring [Member] Real estate assets, net Real Estate Investment Property, Net Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Balances of OP Units Noncontrolling Interest [Table Text Block] Noncontrolling Interest Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Issuance of units upon conversion (in shares) Noncontrolling Interest, Conversion Of Preferred Units To Common Units, Number Of Units Issued Noncontrolling Interest, Conversion Of Preferred Units To Common Units, Number Of Units Issued