Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Other property operating expenses Cost of Other Property Operating Expense Limited Partners' Capital Account by Class [Axis] Limited Partners' Capital Account by Class [Axis] Tenant reinsurance intangible Tenant Reinsurance Intangible [Member] Tenant Reinsurance Intangible [Member] July 2028 Senior Unsecured Notes Senior Unsecured Notes July 2028 [Member] Senior Unsecured Notes July 2028 Net proceeds from sale Proceeds from Sale, Property, Held-for-Sale Partnership Subsidiaries Partnership Subsidiaries [Member] Partnership Subsidiaries [Member] Award Timing Predetermined Award Timing Predetermined [Flag] Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Entity File Number Entity File Number Additional Paid-in Capital Additional Paid-in Capital [Member] Interest Rate Swap Interest Rate Swap [Member] Long Lived Assets Held for Sale Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Equity in earnings (losses) of unconsolidated real estate ventures Equity in (earnings) losses of unconsolidated real estate ventures Equity in (earnings) losses of unconsolidated real estate ventures Income (Loss) from Equity Method Investments Tabular List, Table Tabular List [Table Text Block] Value of common and preferred shares authorized under ATM program Common And Preferred Stock, Value Of Shares Authorized Under ATM Program The maximum value of common and preferred shares permitted to be issued by an entity's at the market program. Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Measurement Basis [Axis] Measurement Basis [Axis] Earnings per share - basic (in dollars per share) Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities November 2031 Senior Unsecured Notes Senior Unsecured Notes November 2031 [Member] Senior Unsecured Notes November 2031 Payment of dividends to preferred shareholders Payments of Ordinary Dividends, Preferred Stock and Preference Stock Stock, Class of Stock [Table] Stock, Class of Stock [Table] Other comprehensive income (loss) Other comprehensive loss Other Comprehensive Income (Loss), Net of Tax Joint Venture Corporate Joint Venture [Member] Schedule of Reporting Segment NOI Schedule of Segment Reporting Information, by Segment [Table Text Block] Adjustment to Compensation, Amount Adjustment to Compensation Amount Unamortized debt issuance costs and debt premium, net Total amortization of premium and unamortized debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Other assets Increase (Decrease) in Other Operating Assets September 2028 Senior Unsecured Notes Senior Unsecured Notes Septmember 2028 [Member] Senior Unsecured Notes Septmember 2028 Principles of Consolidation Consolidation, Policy [Policy Text Block] Equity-based compensation expense Share-Based Payment Arrangement, Noncash Expense Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] VIE, Primary Beneficiary Variable Interest Entity, Primary Beneficiary [Member] Store payroll and related costs Store Payroll And Related Costs Store Payroll And Related Costs Antidilutive Securities [Axis] Antidilutive Securities [Axis] Investment in unconsolidated real estate ventures Payments to Acquire Equity Method Investments Total shareholders' equity Equity, Attributable to Parent Insider Trading Policies and Procedures [Line Items] Common shares of beneficial interest, authorized (in shares) Common Stock, Shares Authorized Segment Reporting, Asset Reconciling Item [Line Items] Segment Reporting, Asset Reconciling Item [Line Items] Hedging Designation [Domain] Hedging Designation [Domain] Private Placement Notes Notes Payable, Fair Value Disclosure Issuance of preferred shares upon redemption of preferred units (in shares) Stock Issued During Period, Shares, New Issues Total liabilities and equity Liabilities and Equity Tenant Warranty Protection or Tenant Insurance Tenant Warranty Protection [Member] Tenant Warranty Protection [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Noncontrolling Interest [Line Items] Noncontrolling Interest [Line Items] Number of assets acquired, properties Number of Properties Number Of Assets Acquired, Properties Number Of Assets Acquired, Properties LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Cover page. Cover [Abstract] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Real estate Real Estate Investment Property, Net [Abstract] Equity Method Investment [Table] Equity Method Investment [Table] Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Accounting Policies [Abstract] Accounting Policies [Abstract] Intangibles Finite-Lived Intangible Assets, Net Self storage property disposed Number Of Self Storage Properties, Disposition Number Of Self Storage Properties, Disposition Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] May 2026 Senior Unsecured Notes 2026 Senior Notes [Member] 2026 Senior Notes Debt financing Total debt Debt, Long-Term and Short-Term, Combined Amount Operating lease liabilities Operating Lease, Liability Mortgage Notes Loans Payable, Fair Value Disclosure Series B Cumulative Redeemable Preferred Shares of Beneficial Interest, par value $0.01 per share Series B Preferred Stock [Member] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Liabilities Liabilities [Abstract] Fixed rate mortgages payable Fixed Rate Mortgages [Member] Fixed Rate Mortgages [Member] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Income before income taxes Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company October 2028 Senior Unsecured Notes Senior Unsecured Notes October 2028 [Member] Senior Unsecured Notes October 2028 Schedule of Carrying Values and Estimated Fair Values of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Proceeds from sale of property Proceeds from Sale of Property, Plant, and Equipment Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Deferred revenue Increase (Decrease) in Deferred Revenue Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Variable Interest Entity [Table] Variable Interest Entity [Table] Unrealized gain (loss) on derivative contracts Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Comprehensive (income) attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Comprehensive income attributable to National Storage Affiliates Trust Comprehensive Income (Loss), Net of Tax, Attributable to Parent Name Measure Name Insurance expense General Insurance Expense Receivable from unconsolidated real estate ventures Other Receivables Secured Debt Secured Debt [Member] Class of Stock [Line Items] Class of Stock [Line Items] Document Fiscal Period Focus Document Fiscal Period Focus DownREIT Partnership DownREIT Partnership [Member] DownREIT Partnership [Member] Property tax expense Real Estate Tax Expense OP units OP units Class A Units [Member] Class A Units [Member] Unsecured debt Unsecured Debt [Member] Award Timing Method Award Timing Method [Text Block] Award Type Award Type [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Legal Entity [Axis] Legal Entity [Axis] Total assets Assets 2029 Long-term Debt, Maturities, Repayments Of Principal In Year Three, Gross Long-term Debt, Maturities, Repayments of Principal in Year Three, Gross Unrealized gains and realized (losses) on interest rate swaps and forward starting swaps included in accumulated other comprehensive income (loss) Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis, Gain (Loss) Included In Other Comprehensive Income (Loss) Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis, Gain (Loss) Included In Other Comprehensive Income (Loss) Investment, Name [Domain] Investment, Name [Domain] Trading Symbol Trading Symbol Restricted Cash Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block] Realized gain (loss), cash flow hedge Realized Gain (Loss), Cash Flow Hedge Realized Gain (Loss), Cash Flow Hedge Entity Address, City or Town Entity Address, City or Town LTIP units Long-Term Incentive Plan Unit [Member] Long-Term Incentive Plan Unit [Member] Other net liabilities assumed Noncash or Part Noncash Acquisition, Other Liabilities Assumed OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] LTIP units with vesting based on service or market condition Long-Term Incentive Plan Unit Based On Service [Member] Long-Term Incentive Plan Unit Based On Service [Member] Self storage properties Total self storage properties Real Estate Investment Property, at Cost Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation [Abstract] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] 2028 Term loan facility 2028 Term Loan Facility [Member] 2028 Term Loan Facility [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Entity Emerging Growth Company Entity Emerging Growth Company Marketing expense Marketing Expense 2029 Long-Term Debt, Maturity, Year Three Variable Interest Entities Consolidation, Variable Interest Entity, Policy [Policy Text Block] Dividends declared per common share (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity Common Stock, Shares Outstanding (in shares) Entity Common Stock, Shares Outstanding Schedule of Units Reflecting Noncontrolling Interests Schedule of Limited Partners' Capital Account by Class [Table Text Block] Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Debt issuance costs, net Debt Issuance Costs, Net October 2026 Senior Unsecured Notes Senior Unsecured Notes October 2026 [Member] Senior Unsecured Notes October 2026 Tenant Insurance and Tenant Warranty Protection Plan Revenues Tenant Insurance And Protection Plan Fees And Commissions [Member] Tenant Insurance And Protection Plan Fees And Commissions [Member] Restricted cash Restricted Cash and Cash Equivalent Investment in unconsolidated real estate ventures Equity Method Investments Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Trade names Indefinite-Lived Intangible Assets (Excluding Goodwill) Customer in-place leases Leases, Acquired-in-Place [Member] Related Party Related Party [Member] Platform fees per unconsolidated real estate venture property per month Platform Fees, Per Joint Venture Property, Per Month Platform Fees, Per Joint Venture Property, Per Month Common shares of beneficial interest, outstanding (in shares) Beginning balances, common stock (in shares) Ending balances, common stock (in shares) Common Stock, Shares, Outstanding Conversion of stock, shares issued Conversion of Stock, Shares Issued PEO PEO [Member] Consolidated properties Consolidated Properties [Member] Supplemental Disclosure of Non-Cash Investing and Financing Activities Noncash Investing and Financing Items [Abstract] Change in assets and liabilities, net of effects of self storage property acquisitions: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Utilities expense Utilities Operating Expense Distributions In Excess Of Earnings Retained Earnings [Member] Accounts payable and accrued liabilities Accounts Payable and Accrued Liabilities Interest rate Debt Instrument, Interest Rate, Effective Percentage Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Beginning of period End of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Interest rate swaps Derivative Asset Income tax expense Income Tax Expense (Benefit) November 2033 Senior Unsecured Notes Senior Unsecured Notes November 2033 [Member] Senior Unsecured Notes November 2033 Sale of Stock [Domain] Sale of Stock [Domain] Other assets, net Other assets Total Other Assets Preferred shares of beneficial interest, issued (in shares) Preferred Stock, Shares Issued Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Hedging Relationship [Axis] Hedging Relationship [Axis] Property Management, Call Center, and Platform Fees Property Management, Call Center, And Platform Fees [Member] Property Management, Call Center, And Platform Fees [Member] Net income Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Discontinued Operations, Held-for-Sale Discontinued Operations, Held-for-Sale [Member] Notional Amount Notional amount Derivative, Notional Amount Property acquisition deposits Earnest Money Deposits Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] OTHER (EXPENSE) INCOME Other Income and Expenses [Abstract] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Series A-1 preferred units Series A-1 Preferred Units [Member] 6.000% Redeemable Series A-1 Preferred Units [Member] City Area Code City Area Code ACQUISITIONS AND DISPOSITIONS Mergers, Acquisitions and Dispositions Disclosures [Text Block] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Mortgages Mortgages [Member] Distributions to preferred shareholders Preferred Stock Dividends, Income Statement Impact 2034 Senior Unsecured Notes 2034 Senior Unsecured Notes [Member] 2034 Senior Unsecured Notes 2027 Long-term Debt, Premium Amortization, Repayments Of Principal In Year One Long-term Debt, Premium Amortization, Repayments Of Principal In Year One Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] General and administrative expenses General and Administrative Expense Change in accrued capital spending Noncash Or Part Noncash Acquisition, Noncash Financial Or Equity Instrument Consideration, Options Issued For Assumed Mortgage Reimbursements Noncash Or Part Noncash Acquisition, Noncash Financial Or Equity Instrument Consideration, Options Issued For Assumed Mortgage Reimbursements Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net Cash Provided by Operating Activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Equity Method Investments and Joint Ventures [Abstract] Equity Method Investments and Joint Ventures [Abstract] Preferred shares of beneficial interest, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Subsequent Event Subsequent Event [Member] Equity Method Investment, Nonconsolidated Investee or Group of Investees Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member] Cash Flow Hedging Cash Flow Hedging [Member] Goodwill Goodwill Other liabilities Other Liabilities Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Fair value at beginning of period Fair value of end of period Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis Fair value, interest rate swap liabilities Derivative Liability, Subject to Master Netting Arrangement, before Offset Equity Components [Axis] Equity Components [Axis] (Gains) and losses on interest rate swaps reclassified into interest expense from accumulated other comprehensive income (loss) Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis, Gain (Loss) Included In Earnings, Reclassification From AOCI, Current Period Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis, Gain (Loss) Included In Earnings, Reclassification From AOCI, Current Period Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Number of reportable segments Number of Reportable Segments Supplemental Cash Flow Information Supplemental Cash Flow Information [Abstract] Other Performance Measure, Amount Other Performance Measure, Amount Debt issuance costs Payments of Debt Issuance Costs Entity Address, State or Province Entity Address, State or Province 2028 Long-term Debt, Premium Amortization, Repayments Of Principal In Year Two Long-term Debt, Premium Amortization, Repayments of Principal in Year Two Net income attributable to common shareholders - diluted Undistributed Earnings (Loss) Available to Common Shareholders, Diluted Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Security, Excluded EPS Calculation [Table] Common share dividends Dividends, Common Stock Related Party [Domain] Related and Nonrelated Parties [Domain] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] NSA OP, LP NSA OP, LP [Member] NSA OP, LP [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Issuance of restricted common shares (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Individual: Individual [Axis] 2029 Long-term Debt, Premium Amortization, Repayments Of Principal In Year Three Long-term Debt, Premium Amortization, Repayments of Principal in Year Three Payment of dividends to common shareholders Payments of Ordinary Dividends, Common Stock Entities [Table] Entities [Table] Entity [Domain] Entity [Domain] Net Cash Used In Investing Activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] 2029 Senior Unsecured Notes 2029 Senior Notes [Member] 2029 Senior Notes [Member] Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Principal payments under debt financings Repayments of Long-Term Debt Entity Interactive Data Current Entity Interactive Data Current Gain on sale of self storage properties Real Estate, Disposition Of Property [Policy Text Block] Real Estate, Disposition Of Property [Policy Text Block] Equity Method Investment, Summarized Financial Information [Abstract] Equity Method Investment, Summarized Financial Information [Abstract] Equity Method Investment, Nonconsolidated Investee [Axis] Equity Method Investment, Nonconsolidated Investee [Axis] Carrying Value Reported Value Measurement [Member] Acquisition and integration costs Acquisition and integration costs Business Combination, Acquisition-Related Cost, Expense Real Estate [Abstract] Real Estate [Abstract] Equity [Abstract] Equity [Abstract] Depreciation and amortization Deprecation, Depletion And Amortization, Excluding Financing Costs And Discounts Deprecation, Depletion and Amortization, Excluding Financing Costs and Discounts Other property-related revenue, Management fees and other revenue Revenue from Contract with Customer [Policy Text Block] 2030 Long-term Debt, Maturities, Repayments Of Principal In Year Four, Gross Long-term Debt, Maturities, Repayments of Principal in Year Four, Gross Segments Segment Reporting Disclosure [Text Block] 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] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis [Roll Forward] Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis [Roll Forward] Fair Value, Net Derivative Asset (Liability) Measured On Recurring Basis [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Number of storage units Number Of Storage Units Number of Storage Units Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] May 2031 Senior Unsecured Notes May 2031 Senior Notes [Member] May 2031 Senior Notes Amortization expense Amortization of Intangible Assets Deposits and advances for self storage properties and other acquisitions Payments for Deposits on Real Estate Acquisitions Supervisory, administrative and other expenses Selling, General and Administrative Expense Capital expenditures Payments for Capital Improvements Amortization of Premium and Unamortized Debt Issuance Costs Maturities Of Long-term Debt, Premium Amortization [Abstract] Maturities Of Long-term Debt, Premium Amortization [Abstract] Entity Central Index Key Entity Central Index Key PEO Name PEO Name October 2030 Senior Unsecured Notes October 2030 Senior Unsecured Notes [Member] October 2030 Senior Unsecured Notes Numerator Earnings Per Share, Diluted, Two Class Method [Abstract] Schedule of Future Debt Maturities Schedule of Maturities of Long-Term Debt [Table Text Block] Total revenue Total revenue Revenues 2027 Long-term Debt, Maturities, Repayments Of Principal In Year One, Gross Long-term Debt, Maturities, Repayments Of Principal In Year One, Gross Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Revolving line of credit Revolving Credit Facility [Member] Retail Products and Supplies Retail Products And Supplies [Member] Retail Products And Supplies [Member] June 2029 Term loan facility June 2029 Term Loan Facility [Member] June 2029 Term Loan Facility Arrangement Duration Trading Arrangement Duration Other Other General Expense Segments [Axis] Segments [Axis] Series A-1 Cumulative Redeemable Preferred Unit Series A-1 Cumulative Redeemable Preferred Unit [Member] Series A-1 Cumulative Redeemable Preferred Unit Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Local Phone Number Local Phone Number Class of Stock [Domain] Class of Stock [Domain] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Thereafter Long-Term Debt, Maturity, after Year Five ASSETS Assets [Abstract] Credit Facility [Axis] Credit Facility [Axis] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Borrowing capacity expansion Line of Credit Facility, Accordion Feature, Increase Limit Line of Credit Facility, Accordion Feature, Increase Limit Debt Instrument [Axis] Debt Instrument [Axis] 2031 Long-term Debt, Premium Amortization, Repayments Of Principal In Year Five Long-term Debt, Premium Amortization, Repayments of Principal in Year Five FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Credit Facility [Domain] Credit Facility [Domain] Buildings and improvements Investment Building and Building Improvements Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Number of states in which self storage properties are located Number of States in which Entity Operates Entity Address, Address Line One Entity Address, Address Line One Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Deferred revenue Deferred Revenue Accumulated Other Comprehensive (Loss) Income AOCI Attributable to Parent [Member] Investment, Name [Axis] Investment, Name [Axis] Real Estate Properties [Domain] Real Estate Properties [Domain] Forward Starting Swaps Forward Starting Swaps [Member] Forward Starting Swaps Schedule of Self Storage Properties Schedule of Real Estate Properties [Table Text Block] Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract] Fair value, other assets, net Derivative Asset, Subject to Master Netting Arrangement, before Offset 2028 Long-term Debt, Maturities, Repayments Of Principal In Year Two, Gross Long-term Debt, Maturities, Repayments of Principal in Year Two, Gross Land Land Fair Value as of Grant Date Award Grant Date Fair Value Accounts receivable Accounts Receivable, after Allowance for Credit Loss Entity Registrant Name Entity Registrant Name Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Unit conversion ratio Equity Instrument, Convertible, Conversion Ratio Equity Instrument, Convertible, Conversion Ratio Vesting and forfeitures of restricted common shares, net Stock Issued During Period, Value, Restricted Stock Award, Vesting And Forfeited Stock Issued During Period, Value, Restricted Stock Award, Vesting And Forfeited Scheduled Principal and Maturity Payments Maturities Of Long Term Debt, Gross [Abstract] Maturities Of Long Term Debt, Gross [Abstract] OP units, DownREIT OP units, Subordinated performance units, DownREIT subordinated performance units OP units, DownREIT OP units, Subordinated performance units, DownREIT subordinated performance units [Member] OP units, DownREIT OP units, Subordinated performance units, DownREIT subordinated performance units [Member] Depreciation expense related to self storage properties Depreciation, Nonproduction Total operating expenses Costs and Expenses Related Party Transaction [Line Items] Related Party Transaction [Line Items] Document Quarterly Report Document Quarterly Report Equity offering costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs August 2031 Senior Unsecured Notes August 2031 Senior Notes [Member] 2031 Senior Notes [Member] Preferred dividends in arrears (in dollars per share) Preferred Stock, Per Share Amounts of Preferred Dividends in Arrears Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Number of operating segments Number of Operating Segments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Acquisition of self storage properties Payments to Acquire Commercial Real Estate May 2033 Senior Unsecured Notes Senior Unsecured Notes May 2033 [Member] Senior Unsecured Notes May 2033 Schedule of Debt Schedule of Debt [Table Text Block] Real Estate Property Ownership [Axis] Real Estate Property Ownership [Axis] Related Party [Axis] Related and Nonrelated Parties [Axis] Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Number of units in real estate property Number of Units in Real Estate Property Restatement Determination Date: Restatement Determination Date [Axis] Non-PEO NEO Non-PEO NEO [Member] Letters of credit outstanding Letters of Credit Outstanding, Amount 2036 Senior Unsecured Notes 2036 Senior Unsecured Notes [Member] 2036 Senior Unsecured Notes Preferred share/unit dividend rate (as a percent) Preferred Stock, Dividend Rate, Percentage Sale of Stock [Axis] Sale of Stock [Axis] Management fees and other revenue Management Fees And Other [Member] Management Fees And Other [Member] Retirement of Northwest Retirement of Northwest [Member] Retirement of Northwest Name Trading Arrangement, Individual Name Redemptions of OP units Stock Issued During Period, Value, Conversion of Units All Award Types Award Type [Domain] Remainder of 2026 Long-Term Debt, Maturity, Remainder of Fiscal Year, Net Long-Term Debt, Maturity, Remainder of Fiscal Year, Net Noncontrolling interests Equity, Attributable to Noncontrolling Interest Equity Awards Adjustments Equity Awards Adjustments [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Compensation Amount Outstanding Recovery Compensation Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] SELF STORAGE PROPERTIES Real Estate Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Total property operating expenses Operating Costs and Expenses Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Estimate of Fair Value Measurement [Member] Preferred Shares Preferred Stock [Member] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name 2023 Joint Venture 2023 Joint Venture [Member] 2023 Joint Venture OTHER ASSETS Other Assets Disclosure [Text Block] Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Asset Acquisition [Line Items] Asset Acquisition [Line Items] REVENUE Revenues [Abstract] October 2033 Senior Unsecured Notes Senior Unsecured Notes October 2033 [Member] Senior Unsecured Notes October 2033 Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax 2027 Long-Term Debt, Maturity, Year One Number of partnerships considered to be VIEs Number Of Partnerships Considered Variable Interest Entities Number Of Partnerships Considered Variable Interest Entities Thereafter Long-term Debt, Maturities, Repayments Of Principal After Year Five, Gross Long-term Debt, Maturities, Repayments Of Principal After Year Five, Gross Segments [Domain] Segments [Domain] 2031 Long-Term Debt, Maturity, Year Five Revolving line of credit remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Thereafter Long-term Debt, Premium Amortization, Repayments Of Principal After Year Five Long-term Debt, Premium Amortization, Repayments Of Principal After Year Five Reclassification of other comprehensive income to interest expense Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Unconsolidated properties Unconsolidated Properties [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Number of top metropolitan statistical areas for focus of operations Number Of Top Metropolitan Statistical Areas For Focus Of Operations Number Of Top Metropolitan Statistical Areas For Focus Of Operations Noncontrolling Interests Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block] Company Selected Measure Name Company Selected Measure Name OP Unit OP Unit [Member] OP Unit Fair Value Measurement [Domain] Fair Value Measurement [Domain] DEBT FINANCING Debt Disclosure [Text Block] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Total principal Total principal Debt, Long-Term And Short-Term, Combined Amounts, Gross Debt, Long-term and Short-term, Combined Amounts, Gross Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Cash and Acquisition Costs Payments For Asset Acquisitions Payments For Asset Acquisitions All Executive Categories All Executive Categories [Member] COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] November 2032 Senior Unsecured Notes Senior Unsecured Notes November 2032 [Member] Senior Unsecured Notes November 2032 Weighted average shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Merger related costs Merger related costs Business Combination, Integration-Related Cost, Expense Commitments and contingencies (Note 11) Commitments and Contingencies Limited Partners' Capital Account, Class [Domain] Limited Partners' Capital Account, Class [Domain] Redemptions of OP units (in shares) Stock Issued During Period, Shares, Conversion of Units Call center fees as percent of monthly gross revenues and net sales revenue of unconsolidated real estate venture assets (as a percent) Call Center Fees, Percent Of Monthly Gross Revenues And Net Sales Revenue Of Joint Venture Assets Call Center Fees, Percent Of Monthly Gross Revenues And Net Sales Revenue Of Joint Venture Assets Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Reconciliation of Assets from Segment to Consolidated [Table] Reconciliation of Assets from Segment to Consolidated [Table] Comprehensive income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Entity Small Business Entity Small Business Outstanding equity interest (in shares) Limited Partners' Capital Account, Units Outstanding Equity offering costs Payments of Stock Issuance Costs November 2030 Senior Unsecured Notes November 2030 Senior Notes [Member] November 2030 Senior Notes Noncontrolling Interests Noncontrolling Interest [Member] Weighted average remaining term (in years) Derivative, Average Remaining Maturity Preferred shares of beneficial interest, outstanding (in shares) Beginning balances, preferred stock (in shares) Ending balances, preferred stock (in shares) Preferred Stock, Shares Outstanding Value of Equity Asset Acquisition, Consideration Transferred, Equity Interest Issued and Issuable Document Transition Report Document Transition Report Investments in Unconsolidated Real Estate Ventures Equity Method Investments [Policy Text Block] Equity-based compensation expense APIC, Share-Based Payment Arrangement, Other, Increase for Cost Recognition Total rentable square feet in self storage properties Net Rentable Area Company's equity interest in unconsolidated real estate ventures (as a percent) Equity Method Investment, Ownership Percentage Noncontrolling Interest [Table] Noncontrolling Interest [Table] Preferred shares of beneficial interest, par value $0.01 per share. 50,000,000 authorized, 14,801,345 and 14,704,845 issued (in series) and outstanding at March 31, 2026 and December 31, 2025, respectively, at liquidation preference Preferred Stock, Value, Outstanding Underlying Securities Award Underlying Securities Amount Term loan D Tranche D Term Loan [Member] Tranche D Term Loan [Member] Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount August 2032 Senior Unsecured Notes Senior Unsecured Notes August 2032 [Member] Senior Unsecured Notes August 2032 Furniture and equipment Fixtures and Equipment, Gross Denominator Earnings Per Share, Diluted [Abstract] Class B Unit Class B Unit [Member] Class B Unit [Member] Common Shares of Beneficial Interest, $0.01 par value per share Common Class A [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Total reportable segment revenue Revenue, Adjusted Revenue, Adjusted Hedging Designation [Axis] Hedging Designation [Axis] Other property-related revenue Other property-related revenue Property Related, Other [Member] Property Related, Other [Member] Schedule of Investments In Self Storage Property Acquisitions Asset Acquisition [Table Text Block] Total equity Beginning balances Ending balances Equity Equity, Including Portion Attributable to Noncontrolling Interest Amortization of debt premium Amortization of Debt Discount (Premium) Document Type Document Type EARNINGS PER SHARE Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Additional paid-in capital Additional Paid in Capital Product and Service [Axis] Product and Service [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Asset Acquisition [Domain] Asset Acquisition [Domain] Revenue Other property-related revenue Management fees and other revenue Revenue from Contract with Customer, Excluding Assessed Tax All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Property management fees as percent of monthly gross revenues and net sales revenue of unconsolidated real estate venture assets (as a percent) Property Management Fees, Percent Of Monthly Gross Revenues And Net Sales Revenue Of Joint Venture Assets Property Management Fees, Percent Of Monthly Gross Revenues And Net Sales Revenue Of Joint Venture Assets Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Term loan E Tranche E Term Loan [Member] Tranche E Term Loan Total Asset Acquisition, Consideration Transferred Name Forgone Recovery, Individual Name Finite-lived intangible assets acquired Finite-Lived Intangible Assets Acquired Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Effect of changes in ownership for consolidated entities Effect Of Changes In Ownership For Consolidated Entities Effect of Changes in Ownership For Consolidated Entities Disposal Group Classification [Axis] Disposal Group Classification [Axis] Authorized amount Share Repurchase Program, Authorized, Amount Reportable Segment Reportable Segment [Member] Reportable Segment Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Number of self storage properties to be sold Number Of Real Estate Properties To Be Disposed Of Number Of Real Estate Properties To Be Disposed Of September 2031 Senior Unsecured Notes Senior Unsecured Notes September 2031 [Member] Senior Unsecured Notes September 2031 Schedule of Other Assets Schedule of Other Assets [Table Text Block] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Derivative term (in years) Derivative, Term of Contract Net income attributable to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Gain on sale of self storage properties Gain (Loss) on Sale of Properties Entity Information [Line Items] Entity Information [Line Items] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Intangible Asset, Finite-Lived [Table] Intangible Asset, Finite-Lived [Table] Schedule Of Reconciliation Of Our Reported Income Before Income Taxes To Our Net Operating Income Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Weighted average fixed rate ( as a percent) Derivative, Average Fixed Interest Rate Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] Gain on sale of self storage properties Gain on sale of self storage properties Gain (Loss) on Disposition of Assets Other Assets Other Assets [Abstract] Finite-lived intangible assets, period increase (decrease) Finite-Lived Intangible Assets, Period Increase (Decrease) Preferred units cash redemption price (in dollars per share) Preferred Stock, Redemption Price Per Share Related Party Transaction [Table] Related Party Transaction [Table] Earnings per share - diluted (in dollars per share) Earnings Per Share, Diluted Distributed and undistributed earnings allocated to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Title of 12(b) Security Title of 12(b) Security Sale of stock, number of shares issued in transaction (in shares) Sale of Stock, Number of Shares Issued in Transaction Total Long-Term Debt, Fiscal Year Maturity [Abstract] Denominator Earnings Per Share [Abstract] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items] Conversion of units (in shares) Conversion of Stock, Shares Converted Other expense, net Nonoperating Income (Expense) 2031 Long-term Debt, Maturities, Repayments Of Principal In Year Five, Gross Long-term Debt, Maturities, Repayments of Principal in Year Five, Gross INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES Equity Method Investments and Joint Ventures Disclosure [Text Block] Asset Acquisition [Table] Asset Acquisition [Table] Prepaid expenses and other Prepaid Expense Other Comprehensive Income (Loss) Comprehensive Income, Policy [Policy Text Block] Distributions to noncontrolling interests Distribution Made to Limited Partner, Cash Distributions Paid Award Timing Disclosures [Line Items] Credit Facility: Credit Facility [Member] Credit Facility [Member] Estimated fair value of net assets acquired Asset Acquisition, Assets Acquired and Liabilities Assumed, Net Asset Acquisition, Assets Acquired and Liabilities Assumed, Net Assets held for sale, net Asset, Held-for-Sale, Not Part of Disposal Group SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS Equity [Text Block] Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Trade names Trade Names [Member] Net income attributable to National Storage Affiliates Trust Net Income (Loss) Attributable to Parent Subsequent Event [Table] Subsequent Event [Table] Expiration Date Trading Arrangement Expiration Date Equity Method Investment, Nonconsolidated Investee [Domain] Equity Method Investment, Nonconsolidated Investee [Domain] 2030 Long-term Debt, Premium Amortization, Repayments Of Principal In Year Four Long-term Debt, Premium Amortization, Repayments of Principal in Year Four Self storage properties, net Self storage properties, net Real Estate Investment Property, Net 2016 Joint Venture 2016 Joint Venture [Member] 2016 Joint Venture Equity Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Corporate furniture, equipment and other, net Property, Plant and Equipment, Net Prior Sales Agreement Prior At The Market Sales Agreement [Member] Prior At The Market Sales Agreement Schedule of Condensed Financial Position and Condensed Operating Information Equity Method Investments [Table Text Block] Preferred shares of beneficial interest, authorized (in shares) Preferred Stock, Shares Authorized Adoption Date Trading Arrangement Adoption Date Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Series A Preferred Shares Series A Preferred Stock [Member] Entity Current Reporting Status Entity Current Reporting Status Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Net operating income Net operating income Operating Income (Loss) Redemption of OP units Payments For Repurchase Of OP Equity Payments For Repurchase Of OP Equity Line of Credit Line of Credit Line of Credit [Member] Consolidated Entities [Domain] Consolidated Entities [Domain] Series A Cumulative Redeemable Preferred Shares of Beneficial Interest, par value $0.01 per share Redeemable Preferred Stock [Member] Distributions in excess of earnings Retained Earnings (Accumulated Deficit) Net gain on disposition Gain (Loss) on Disposition of Property Plant Equipment Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Executive Category: Executive Category [Axis] Rental revenue Revenue Recognition, Leases [Policy Text Block] Other comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Minimum conversion period (in years) Stockholders Equity Note, Unit Conversion, Minimum Conversion Period Stockholders Equity Note, Unit Conversion, Minimum Conversion Period Borrowings under debt financings Proceeds from Issuance of Long-Term Debt Current Fiscal Year End Date Current Fiscal Year End Date Class of Stock [Axis] Class of Stock [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Percent of total warranty protection plan proceeds received per unconsolidated real estate venture property (as a percent) Tenant Warranty Plan, Proceeds Per Property, Percent Tenant Warranty Plan, Proceeds Per Property, Percent Management contract Service Agreements [Member] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Expenditures for corporate furniture, equipment and other Payments to Acquire Furniture and Fixtures Non-operating (expense) income Non-operating (expense) Non-operating expense (income) Other Nonoperating Income (Expense) Statement [Table] Statement [Table] Interest rate swap liabilities Derivative Liability Adjustments to reconcile net income to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] At The Market Program At The Market Program [Member] At The Market Program FINANCING ACTIVITIES Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Receivables: Accounts Receivable, after Allowance for Credit Loss [Abstract] Distributions from unconsolidated real estate ventures Proceeds from Equity Method Investment, Distribution ORGANIZATION AND NATURE OF OPERATIONS Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Equity interests excluded from computation of diluted earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount All Adjustments to Compensation All Adjustments to Compensation [Member] Amendment Flag Amendment Flag 2028 Long-Term Debt, Maturity, Year Two Net proceeds from sale of self storage properties Proceeds from Sale, Real Estate, Held-for-Investment 2018 Joint Venture 2018 Joint Venture [Member] 2018 Joint Venture Third Party Third Party [Member] Third Party Termination Date Trading Arrangement Termination Date Repairs & maintenance expense Utilities Operating Expense, Maintenance Net Cash Used In Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Measure: Measure [Axis] Number of Contracts Number of Interest Rate Derivatives Held Cash and Cash Equivalents Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block] August 2030 Senior Unsecured Notes August 2030 Senior Notes [Member] August 2030 Senior Notes Weighted average shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Remaining authorized, amount Share Repurchase Program, Remaining Authorized, Amount Disposal Group Classification [Domain] Disposal Group Classification [Domain] Schedule of the Computation of Basic and Diluted Earnings Per Common Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Subsequent Events [Abstract] Subsequent Events [Abstract] Segment Reporting [Abstract] Property operating expenses Property operating expenses Cost of Revenue Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Value of remaining available offered shares Common And Preferred Stock, Remaining Value of Shares Authorized Under ATM Program Common And Preferred Stock, Remaining Value of Shares Authorized Under ATM Program Debt Disclosure [Abstract] Debt Disclosure [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Amortization of debt issuance costs Amortization of Debt Issuance Costs Interest rate (as a percent) Derivative, Forward Interest Rate Entity Tax Identification Number Entity Tax Identification Number Net income attributable to common shareholders - basic Undistributed Earnings (Loss) Available to Common Shareholders, Basic Remainder of 2026 Long-term Debt, Premium Amortization, Repayments Of Principal, Remainder Of Year Long-term Debt, Premium Amortization, Repayments of Principal, Remainder of Year Asset Acquisition [Axis] Asset Acquisition [Axis] Number of self storage properties Number of Real Estate Properties Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Consolidated Entities [Axis] Consolidated Entities [Axis] Common shares of beneficial interest, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common shares of beneficial interest, issued (in shares) Common Stock, Shares, Issued Derivative Asset, Statement of Financial Position [Extensible Enumeration] Derivative Asset, Statement of Financial Position [Extensible Enumeration] 2030 Long-Term Debt, Maturity, Year Four Use of Estimates Use of Estimates, Policy [Policy Text Block] Interest expense Interest expense Interest Expense, Nonoperating Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Number of units issued (in units) Conversion Of Stock, Number Of Units Issues Conversion Of Stock, Number Of Units Issues Rental revenue Operating Lease, Lease Income Schedule of Interest Rate Swap Derivatives Measured at Fair Value Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] SUBSEQUENT EVENTS Subsequent Events [Text Block] Insider Trading Arrangements [Line Items] 2024 Joint Venture 2024 Joint Venture [Member] 2024 Joint Venture Security Exchange Name Security Exchange Name Schedule Of Reconciliation Of Our Reportable Segment Revenue To Total Revenue Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Total liabilities Liabilities Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Preferred share dividends Dividends, Preferred Stock Common shares of beneficial interest, par value $0.01 per share. 250,000,000 authorized, 77,137,402 and 77,089,734 shares issued and outstanding at March 31, 2026 and December 31, 2025, respectively Common Stock, Value, Outstanding Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] April 2029 Term loan facility April 2029 Term Loan Facility [Member] April 2029 Term Loan Facility Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-Lived Intangible Assets, Major Class Name [Domain] OPERATING EXPENSES Operating Expenses [Abstract] Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Remainder of 2026 Long-term Debt, Maturities, Repayments Of Principal, Remainder Of Year, Gross Long-term Debt, Maturities, Repayments of Principal, Remainder Of Year, Gross Issuance of preferred shares upon redemption of preferred units Stock Issued During Period, Value, New Issues Statement [Line Items] Statement [Line Items] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Subsequent Event [Line Items] Subsequent Event [Line Items] Common Shares Common Stock [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Vesting and forfeitures of restricted common shares, net (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Vesting And Forfeited Stock Issued During Period, Shares, Restricted Stock Award, Vesting And Forfeited Non-NEOs Non-NEOs [Member] Other Asset Acquisitions, Liabilities And Other Consideration Asset Acquisitions, Liabilities And Other Consideration Less accumulated depreciation Real Estate Investment Property, Accumulated Depreciation Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation