Annual report pursuant to Section 13 and 15(d)

RELATED PARTY TRANSACTIONS (Details)

v3.24.0.1
RELATED PARTY TRANSACTIONS (Details)
$ in Thousands
 3 Months Ended 12 Months Ended
Jan. 01, 2023
USD ($)
shares
Jan. 01, 2022
USD ($)
shares
Dec. 31, 2021
USD ($)
shares
Dec. 31, 2023
USD ($)
property
Sep. 30, 2023
USD ($)
property
Jun. 30, 2023
USD ($)
property
Mar. 31, 2023
USD ($)
property
Dec. 31, 2022
USD ($)
property
Sep. 30, 2022
USD ($)
property
Jun. 30, 2022
USD ($)
property
Mar. 31, 2022
USD ($)
property
Dec. 31, 2023
USD ($)
property
Dec. 31, 2022
USD ($)
property
Dec. 31, 2021
USD ($)
property
shares
Related Party Transaction [Line Items]                            
Property operating expenses                       $ 228,986 $ 211,025 $ 155,265
Number of properties acquired | property       2 2 0 16 2 23 8 12 20 45  
Gross sales price of acquisition       $ 25,022 $ 30,114 $ 13,778 $ 160,536 $ 39,919 $ 321,789 $ 114,533 $ 92,935 $ 229,450 $ 569,176  
Value of OP equity       $ 8,062 $ 16,370 $ 5,577 $ 150,531 $ 32,141 $ 6,244 $ 13,938 $ 16,576 180,540 68,899  
Reinsurance Company                            
Related Party Transaction [Line Items]                            
Ownership interest in reinsurance company acquired (percent)     0.54%                     0.54%
Series NW                            
Related Party Transaction [Line Items]                            
Issuance of shares/units (in shares) | shares   2,078,357                        
Series MI                            
Related Party Transaction [Line Items]                            
Issuance of shares/units (in shares) | shares 926,623                          
OP Units                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares 2,545,063 3,911,260                        
Self Storage Property Purchase | Affiliated entity | OP units                            
Related Party Transaction [Line Items]                            
Shares issued in connection with asset acquisition (in shares) | shares                           31,869
Value of OP equity                           $ 2,100
Self Storage Property Purchase | Affiliate Entity Via Trustee                            
Related Party Transaction [Line Items]                            
Number of properties acquired | property                           8
Gross sales price of acquisition                           $ 102,700
Self Storage Property Purchase | Affiliated Entity via Trustee and Trustee's Children | OP units                            
Related Party Transaction [Line Items]                            
Shares issued in connection with asset acquisition (in shares) | shares                           171,439
Value of OP equity                           $ 10,200
Acquisition of interest in reinsurance company | Affiliated entity | OP units | Reinsurance Company                            
Related Party Transaction [Line Items]                            
Shares issued in connection with business acquisition (in shares) | shares     48,128                      
Value of OP units issued in acquisition     $ 3,300                      
PRO | Supervisory and administrative fee agreement | Affiliate                            
Related Party Transaction [Line Items]                            
Administrative expense                       21,200 22,600 20,400
PRO | Payroll services | Management                            
Related Party Transaction [Line Items]                            
Property operating expenses                       26,700 29,300 27,900
PRO | Due diligence costs | Management                            
Related Party Transaction [Line Items]                            
Operating costs and expenses                       $ 25 $ 400 $ 1,700
PRO | Minimum | Supervisory and administrative fee agreement | Management                            
Related Party Transaction [Line Items]                            
Supervisory and administrative fee arrangement of gross revenue (percent)                       5.00%    
PRO | Maximum | Supervisory and administrative fee agreement | Management                            
Related Party Transaction [Line Items]                            
Supervisory and administrative fee arrangement of gross revenue (percent)                       6.00%    
J. Timothy Warren | Affiliated entity | Series NW                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares   7,021                        
J. Timothy Warren | Affiliated entity | OP Units                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares   13,213                        
Conversion of stock   $ 900                        
Mr. Nordhagen | Affiliated entity | Series MI                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares 163,128                          
Mr. Nordhagen | Affiliated entity | OP Units                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares 448,047                          
Conversion of stock $ 9,800                          
Mr. Cramer | Affiliated entity | Series MI                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares 74,617                          
Mr. Cramer | Affiliated entity | OP Units                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares 204,943                          
Conversion of stock $ 4,500                          
J. Timothy Warren's Adult Children | Affiliated entity | Series NW                            
Related Party Transaction [Line Items]                            
Number of units converted (in units) | shares   157,149                        
J. Timothy Warren's Adult Children | Affiliated entity | OP Units                            
Related Party Transaction [Line Items]                            
Conversion of stock   $ 20,500                        
Shares issued in connection with asset acquisition (in shares) | shares   295,739                        
Kevin Howard Real Estate, Inc. | Acquisition of interest in reinsurance company | Reinsurance Company                            
Related Party Transaction [Line Items]                            
Consideration in acquisition transaction     9,500                      
Cash paid in acquisition     $ 2,900                      
Kevin Howard Real Estate, Inc. | Acquisition of interest in reinsurance company | OP units | Reinsurance Company                            
Related Party Transaction [Line Items]                            
Shares issued in connection with business acquisition (in shares) | shares     96,256                      
Value of OP units issued in acquisition     $ 6,600