Investment in Storage Facilities and Intangible Assets - Schedule of Purchase Price of Facilities Acquired (Detail) $ in Thousands | 6 Months Ended |
Jun. 30, 2021USD ($)Property | Jun. 30, 2020Property |
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. 4, 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. 4, 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 3, 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. 1, 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 | |