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Property Management Fees, Percent Of Monthly Gross Revenues And Net Sales Revenue Of Joint Venture Assets

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SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	3 Months Ended
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	Mar. 31, 2026 USD ($) property partnership	Mar. 31, 2025 USD ($)	Mar. 16, 2026 property	Dec. 31, 2025 USD ($)
Variable Interest Entity [Line Items]
Number of self storage properties \| property	1,061		313
Self storage properties, net	$ 4,576,141,000			$ 4,601,317,000
Total principal	3,425,441,000			3,414,508,000
Assets held for sale, net	$ 1,086,000			14,519,000
Property management fees as percent of monthly gross revenues and net sales revenue of unconsolidated real estate venture assets (as a percent)	4.00%
Discontinued Operations, Held-for-Sale \| Third Party
Variable Interest Entity [Line Items]
Number of self storage properties to be sold \| property	3
Tenant Insurance and Tenant Warranty Protection Plan Revenues
Variable Interest Entity [Line Items]
Revenue	$ 5,000,000.0	$ 5,900,000
Retail Products and Supplies
Variable Interest Entity [Line Items]
Revenue	300,000	400,000
Property Management, Call Center, and Platform Fees
Variable Interest Entity [Line Items]
Revenue	$ 4,800,000	4,700,000
Property management fees as percent of monthly gross revenues and net sales revenue of unconsolidated real estate venture assets (as a percent)	6.00%
Platform fees per unconsolidated real estate venture property per month	$ 1,250
Call center fees as percent of monthly gross revenues and net sales revenue of unconsolidated real estate venture assets (as a percent)	1.00%
Tenant Warranty Protection or Tenant Insurance
Variable Interest Entity [Line Items]
Revenue	$ 6,500,000	$ 7,200,000
Percent of total warranty protection plan proceeds received per unconsolidated real estate venture property (as a percent)	50.00%
Fixed rate mortgages payable \| Mortgages
Variable Interest Entity [Line Items]
Total principal	$ 198,041,000			198,608,000
VIE, Primary Beneficiary
Variable Interest Entity [Line Items]
Number of partnerships considered to be VIEs \| partnership	22
Number of self storage properties \| property	49
Self storage properties, net	$ 392,900,000			395,800,000
VIE, Primary Beneficiary \| Fixed rate mortgages payable \| Mortgages
Variable Interest Entity [Line Items]
Total principal	$ 172,900,000			$ 172,900,000