Quarterly report pursuant to Section 13 or 15(d)

SUBSEQUENT EVENTS (Details)

v3.21.2
SUBSEQUENT EVENTS (Details)
1 Months Ended 3 Months Ended 6 Months Ended
Jul. 23, 2021
USD ($)
$ / shares
shares
Aug. 04, 2021
USD ($)
property
$ / shares
shares
Jun. 30, 2021
USD ($)
$ / shares
shares
Mar. 31, 2021
USD ($)
Jun. 30, 2021
USD ($)
$ / shares
shares
Sep. 30, 2021
USD ($)
Jul. 09, 2021
USD ($)
property
Subsequent Event [Line Items]              
Consideration in acquisition transaction     $ 269,393,000 $ 165,963,000 $ 435,356,000    
Cash paid in asset acquisition     243,580,000 141,928,000 385,508,000    
Other liabilities assumed in asset acquisition     1,711,000 1,138,000 2,849,000    
Value of OP equity issued in asset acquisition     24,102,000 $ 22,897,000 46,999,000    
Credit Facility | Unsecured debt              
Subsequent Event [Line Items]              
Maximum borrowing capacity     $ 1,275,000,000   $ 1,275,000,000    
Credit Facility | Unsecured debt | Term loan E | Forecast              
Subsequent Event [Line Items]              
Maximum borrowing capacity           $ 100,000,000.0  
Common shares | At the Market Program              
Subsequent Event [Line Items]              
Sale of stock, number of shares issued in transaction (in shares) | shares     2,390,000   3,032,726    
Proceeds from sale of stock     $ 103,700,000   $ 129,100,000    
Average price per share (in dollars per share) | $ / shares     $ 43.86   $ 42.92    
Self storage property purchase from affiliate of trustee | Affiliated entity              
Subsequent Event [Line Items]              
Consideration in acquisition transaction         $ 8,800,000    
OP units | Self storage property purchase from affiliate of trustee | Affiliated entity | Mr. J. Timothy Warren              
Subsequent Event [Line Items]              
Value of OP equity issued in asset acquisition         $ 1,100,000    
Number of OP Units in acquisition (in shares) | shares         29,123    
Subsequent Event              
Subsequent Event [Line Items]              
Number of properties acquired | property   7          
Consideration in acquisition transaction   $ 68,600,000          
Cash paid in asset acquisition   57,100,000          
Other liabilities assumed in asset acquisition   200,000          
Value of OP equity issued in asset acquisition   $ 11,300,000          
Subsequent Event | 2028 Fixed Rate Mortgage Payable | Fixed rate mortgages payable              
Subsequent Event [Line Items]              
Debt issued             $ 88,000,000.0
Number of properties securing debt | property             8
Interest rate             2.77%
Subsequent Event | Common shares | Follow-On Public Offering              
Subsequent Event [Line Items]              
Sale of stock, number of shares issued in transaction (in shares) | shares 10,120,000            
Sale of stock, price per share (in dollars per share) | $ / shares $ 51.25            
Proceeds from sale of stock $ 497,400,000            
Subsequent Event | Common shares | At the Market Program              
Subsequent Event [Line Items]              
Sale of stock, number of shares issued in transaction (in shares) | shares   782,000          
Proceeds from sale of stock   $ 40,000,000.0          
Average price per share (in dollars per share) | $ / shares   $ 51.82          
Subsequent Event | Underwriter option to purchase | Follow-On Public Offering              
Subsequent Event [Line Items]              
Sale of stock, number of shares issued in transaction (in shares) | shares 1,320,000            
Subsequent Event | Self storage property purchase from affiliate of trustee | Affiliated entity              
Subsequent Event [Line Items]              
Number of properties acquired | property   1          
Consideration in acquisition transaction   $ 11,700,000          
Subsequent Event | OP units              
Subsequent Event [Line Items]              
Number of OP Units in acquisition (in shares) | shares   189,322          
Subsequent Event | OP units | Self storage property purchase from affiliate of trustee | Affiliated entity | Mr. J. Timothy Warren              
Subsequent Event [Line Items]              
Value of OP equity issued in asset acquisition   $ 500,000          
Number of OP Units in acquisition (in shares) | shares   9,290          
Subsequent Event | Subordinated performance units              
Subsequent Event [Line Items]              
Number of OP Units in acquisition (in shares) | shares   10,870