Annual report pursuant to Section 13 and 15(d)

SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS - Equity Interests (Details)

v3.22.0.1
SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS - Equity Interests (Details) - shares
Dec. 31, 2021
Dec. 31, 2020
Partnership Subsidiaries    
Noncontrolling Interest [Line Items]    
Outstanding equity interest (in shares) 49,325,110 46,281,288
Series A-1 preferred units | NSA OP, LP    
Noncontrolling Interest [Line Items]    
Outstanding equity interest (in shares) 640,047 637,382
OP units | NSA OP, LP    
Noncontrolling Interest [Line Items]    
Outstanding equity interest (in shares) 31,893,105 29,616,809
OP units | DownREIT Partnership    
Noncontrolling Interest [Line Items]    
Outstanding equity interest (in shares) 1,924,918 1,924,918
Subordinated performance units | NSA OP, LP    
Noncontrolling Interest [Line Items]    
Outstanding equity interest (in shares) 9,754,482 9,030,872
Subordinated performance units | DownREIT Partnership    
Noncontrolling Interest [Line Items]    
Outstanding equity interest (in shares) 4,337,111 4,337,111
LTIP units | NSA OP, LP    
Noncontrolling Interest [Line Items]    
Outstanding equity interest (in shares) 775,447 734,196