SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS - Equity Interests (Details) - shares	Mar. 31, 2024	Dec. 31, 2023
Partnership Subsidiaries
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	53,959,142	53,879,191
Series A-1 preferred units | NSA OP, LP
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	1,212,340	1,212,340
OP units | NSA OP, LP
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	37,658,350	37,635,683
OP units | DownREIT Partnership
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	2,120,491	2,120,491
Subordinated performance units | NSA OP, LP
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	7,967,581	7,991,271
Subordinated performance units | DownREIT Partnership
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	4,133,474	4,133,474
LTIP units | NSA OP, LP
Noncontrolling Interest [Line Items]
Outstanding equity interest (in shares)	866,906	785,932