National Storage Affiliates Trust Annual report pursuant to Section 13 and 15(d)

ORGANIZATION AND NATURE OF OPERATIONS - Narrative (Details) storage_unit in Thousands, ft² in Millions	12 Months Ended
	Dec. 31, 2022 ft² property storage_unit state metropolitan_statistical_area	Jan. 01, 2023 property
Real Estate Properties [Line Items]
Number of top metropolitan statistical areas for focus of operations \| metropolitan_statistical_area	100
Number of self storage properties	1,101
Number of states in which self storage properties are located \| state	42
Total rentable square feet in self storage properties \| ft²	71.8
Number of storage units	564,000
Joint Venture \| Subsequent Event
Real Estate Properties [Line Items]
Number of self storage properties		72
Consolidated properties
Real Estate Properties [Line Items]
Number of self storage properties	916
Number of states in which self storage properties are located \| state	39
Total rentable square feet in self storage properties \| ft²	58.3
Number of storage units \| storage_unit	453
Unconsolidated properties \| Joint Venture
Real Estate Properties [Line Items]
Number of self storage properties	185
Number of states in which self storage properties are located \| state	21
Total rentable square feet in self storage properties \| ft²	13.5
Number of storage units	111,000