INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Condensed Operating Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Related Party Transaction [Line Items]
Total revenue	$ 188,354	$ 196,148
Property operating expenses	(55,104)	(54,694)
Depreciation and amortization	(48,116)	(47,331)
Interest expense	(40,475)	(38,117)
Acquisition and integration costs	(2,445)	(507)
Net income attributable to National Storage Affiliates Trust	12,994	59,027
Joint Venture | Equity Method Investment, Nonconsolidated Investee or Group of Investees
Related Party Transaction [Line Items]
Total revenue	61,624	56,096
Property operating expenses	(22,416)	(17,603)
Supervisory, administrative and other expenses	(4,041)	(3,658)
Depreciation and amortization	(21,644)	(18,206)
Interest expense	(13,645)	(12,100)
Acquisition and integration costs	(150)	(59)
Net income attributable to National Storage Affiliates Trust	$ (272)	$ 4,470