Quarterly report pursuant to Section 13 or 15(d)

Investment in Storage Facilities and Intangible Assets - Schedule of Purchase Price of Facilities Acquired (Detail)

v3.21.2
Investment in Storage Facilities and Intangible Assets - Schedule of Purchase Price of Facilities Acquired (Detail)
$ in Thousands
 6 Months Ended
Jun. 30, 2021
USD ($)
Property
Jun. 30, 2020
Property
Investment Holdings [Line Items]    
Number of Properties | Property 33 6
Purchase Price $ 533,710  
Consideration paid, Cash Paid 531,109  
Consideration paid, Net Other Liabilities (Assets) Assumed 2,601  
Acquisition Date Fair Value, In-Place Customer Leases 6,468  
Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 86,347  
Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 440,867  
SC [Member] | Asset Acquired on 1/4/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 1  
Date of Acquisition Jan. 04, 2021  
Purchase Price $ 8,070  
Consideration paid, Cash Paid 8,042  
Consideration paid, Net Other Liabilities (Assets) Assumed 28  
Acquisition Date Fair Value, In-Place Customer Leases 105  
SC [Member] | Asset Acquired on 1/4/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 812  
SC [Member] | Asset Acquired on 1/4/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 7,153  
CA [Member] | Asset Acquired on 1/21/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 1  
Date of Acquisition Jan. 21, 2021  
Purchase Price $ 18,287  
Consideration paid, Cash Paid 18,251  
Consideration paid, Net Other Liabilities (Assets) Assumed 36  
Acquisition Date Fair Value, In-Place Customer Leases 135  
CA [Member] | Asset Acquired on 1/21/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 1,322  
CA [Member] | Asset Acquired on 1/21/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 16,830  
NY [Member] | Asset Acquired on 3/4/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 1  
Date of Acquisition Mar. 04, 2021  
Purchase Price $ 47,947  
Consideration paid, Cash Paid 47,933  
Consideration paid, Net Other Liabilities (Assets) Assumed 14  
Acquisition Date Fair Value, In-Place Customer Leases 336  
NY [Member] | Asset Acquired on 3/4/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 10,591  
NY [Member] | Asset Acquired on 3/4/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 37,020  
Florida [Member] | Asset Acquired on 3/11/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 8  
Date of Acquisition Mar. 11, 2021  
Purchase Price $ 85,156  
Consideration paid, Cash Paid 84,586  
Consideration paid, Net Other Liabilities (Assets) Assumed 570  
Acquisition Date Fair Value, In-Place Customer Leases 1,237  
Florida [Member] | Asset Acquired on 3/11/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 13,381  
Florida [Member] | Asset Acquired on 3/11/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 70,538  
Florida [Member] | Asset Acquired On 5/3/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 1  
Date of Acquisition May 03, 2021  
Purchase Price $ 16,545  
Consideration paid, Cash Paid 16,497  
Consideration paid, Net Other Liabilities (Assets) Assumed 48  
Acquisition Date Fair Value, In-Place Customer Leases 148  
Florida [Member] | Asset Acquired On 5/3/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 1,658  
Florida [Member] | Asset Acquired On 5/3/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 14,739  
Florida [Member] | Asset Acquired On 6/16/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 1  
Date of Acquisition Jun. 16, 2021  
Purchase Price $ 14,344  
Consideration paid, Cash Paid 14,235  
Consideration paid, Net Other Liabilities (Assets) Assumed 109  
Acquisition Date Fair Value, In-Place Customer Leases 217  
Florida [Member] | Asset Acquired On 6/16/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 2,601  
Florida [Member] | Asset Acquired On 6/16/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 11,526  
AZ [Member] | Asset Acquired on 3/24/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 3  
Date of Acquisition Mar. 24, 2021  
Purchase Price $ 67,089  
Consideration paid, Cash Paid 66,890  
Consideration paid, Net Other Liabilities (Assets) Assumed 199  
Acquisition Date Fair Value, In-Place Customer Leases 632  
AZ [Member] | Asset Acquired on 3/24/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 7,129  
AZ [Member] | Asset Acquired on 3/24/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 59,320  
WA [Member] | Asset Acquired on 3/25/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 2  
Date of Acquisition Mar. 25, 2021  
Purchase Price $ 39,666  
Consideration paid, Cash Paid 39,495  
Consideration paid, Net Other Liabilities (Assets) Assumed 171  
Acquisition Date Fair Value, In-Place Customer Leases 443  
WA [Member] | Asset Acquired on 3/25/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 6,166  
WA [Member] | Asset Acquired on 3/25/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 33,037  
NJ [Member] | Asset Acquired On 5/12/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 5  
Date of Acquisition May 12, 2021  
Purchase Price $ 90,944  
Consideration paid, Cash Paid 90,710  
Consideration paid, Net Other Liabilities (Assets) Assumed 234  
Acquisition Date Fair Value, In-Place Customer Leases 1,271  
NJ [Member] | Asset Acquired On 5/12/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 11,557  
NJ [Member] | Asset Acquired On 5/12/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 78,116  
NC [Member] | Asset Acquired On 6/1/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 2  
Date of Acquisition Jun. 01, 2021  
Purchase Price $ 26,942  
Consideration paid, Cash Paid 26,793  
Consideration paid, Net Other Liabilities (Assets) Assumed 149  
Acquisition Date Fair Value, In-Place Customer Leases 338  
NC [Member] | Asset Acquired On 6/1/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 2,209  
NC [Member] | Asset Acquired On 6/1/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 24,395  
NC [Member] | Asset Acquired On 6/23/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 1  
Date of Acquisition Jun. 23, 2021  
Purchase Price $ 14,539  
Consideration paid, Cash Paid 14,468  
Consideration paid, Net Other Liabilities (Assets) Assumed 71  
Acquisition Date Fair Value, In-Place Customer Leases 187  
NC [Member] | Asset Acquired On 6/23/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 657  
NC [Member] | Asset Acquired On 6/23/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 13,695  
TX [Member] | Asset Acquired On 6/10/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 4  
Date of Acquisition Jun. 10, 2021  
Purchase Price $ 44,563  
Consideration paid, Cash Paid 43,952  
Consideration paid, Net Other Liabilities (Assets) Assumed 611  
Acquisition Date Fair Value, In-Place Customer Leases 654  
TX [Member] | Asset Acquired On 6/10/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 9,163  
TX [Member] | Asset Acquired On 6/10/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 34,746  
FL And NH [Member] | Asset Acquired On 6/22/2021 [Member]    
Investment Holdings [Line Items]    
Number of Properties | Property 3  
Date of Acquisition Jun. 22, 2021  
Purchase Price $ 59,618  
Consideration paid, Cash Paid 59,257  
Consideration paid, Net Other Liabilities (Assets) Assumed 361  
Acquisition Date Fair Value, In-Place Customer Leases 765  
FL And NH [Member] | Asset Acquired On 6/22/2021 [Member] | Land [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets 19,101  
FL And NH [Member] | Asset Acquired On 6/22/2021 [Member] | Building, Equipment and Improvements [Member]    
Investment Holdings [Line Items]    
Acquisition Date Fair Value, Fixed Assets $ 39,752