Organization - Additional Information (Detail)					3 Months Ended
	May 28, 2021 USD ($)	Mar. 10, 2021 USD ($) shares	Feb. 26, 2021 USD ($)	Jan. 15, 2021 USD ($) $ / shares shares	Mar. 31, 2022 USD ($) Employee UnconsolidatedRealEstateVenture $ / shares shares	Mar. 31, 2021 shares	Dec. 31, 2021 $ / shares shares
Organization And Nature Of Operations [Line Items]
Date of formation of company					Oct. 14, 2020
Number of employees | Employee					0
Preferred Stock, shares authorized | shares				200,000,000	200,000,000		200,000,000
Preferred Stock, par value | $ / shares				$ 0.001	$ 0.001		$ 0.001
Shares issuable pursuant to distribution reinvestment plan			$ 20,000,000
Equity ownership percentage					50.00%
Percentage of non-voting economic interest owned by affiliates					10.00%
Number of unconsolidated real estate ventures | UnconsolidatedRealEstateVenture					2
Advisor purchased initial investment in operating partnership					$ 202,000
SmartCentres
Organization And Nature Of Operations [Line Items]
Equity ownership percentage					50.00%
Maximum
Organization And Nature Of Operations [Line Items]
Common stock, value authorized			200,000,000
Class A Common Stock
Organization And Nature Of Operations [Line Items]
Common Stock, shares authorized | shares				300,000,000	300,000,000		0
Common Stock, par value | $ / shares					$ 0.001		$ 0.001
Class A Common Stock | Primary Offering | Maximum
Organization And Nature Of Operations [Line Items]
Common stock, value authorized	$ 1,000,000,000
Class A Common Stock | Pubic Offering
Organization And Nature Of Operations [Line Items]
Shares issuable pursuant to distribution reinvestment plan	95,000,000
Class P Common Stock
Organization And Nature Of Operations [Line Items]
Common Stock, shares authorized | shares				30,000,000	30,000,000		30,000,000
Common Stock, par value | $ / shares					$ 0.001		$ 0.001
Class P Common Stock | Common Stock
Organization And Nature Of Operations [Line Items]
Gross proceeds from issuance of common stock					$ 99,700,000
Common stock issued in connection with offering | shares					5,430,060	5,666
Class P Common Stock | Private Offering | Common Stock
Organization And Nature Of Operations [Line Items]
Common stock issued in connection with offering | shares					10,500,000
Class T Common Stock
Organization And Nature Of Operations [Line Items]
Common Stock, shares authorized | shares				300,000,000	300,000,000		0
Common Stock, par value | $ / shares					$ 0.001		$ 0.001
Class T Common Stock | Primary Offering | Maximum
Organization And Nature Of Operations [Line Items]
Common stock, value authorized	1,000,000,000
Class T Common Stock | Pubic Offering
Organization And Nature Of Operations [Line Items]
Shares issuable pursuant to distribution reinvestment plan	95,000,000
Class W Common Stock
Organization And Nature Of Operations [Line Items]
Common Stock, shares authorized | shares				70,000,000	70,000,000		0
Common Stock, par value | $ / shares					$ 0.001		$ 0.001
Class W Common Stock | Primary Offering | Maximum
Organization And Nature Of Operations [Line Items]
Common stock, value authorized	1,000,000,000
Class W Common Stock | Pubic Offering
Organization And Nature Of Operations [Line Items]
Shares issuable pursuant to distribution reinvestment plan	$ 95,000,000
Articles of Incorporation
Organization And Nature Of Operations [Line Items]
Common Stock, shares authorized | shares				30,000
Common Stock, par value | $ / shares				$ 0.001
Articles of Amendment and Restatement
Organization And Nature Of Operations [Line Items]
Common Stock, shares authorized | shares				700,000,000
Common Stock, par value | $ / shares				$ 0.001
Strategic Storage Advisor IV, LLC
Organization And Nature Of Operations [Line Items]
Sale of common shares to advisor				$ 1,000
Advisor purchased initial investment in operating partnership				$ 1,000
Strategic Storage Advisor IV, LLC | Class A Common Stock
Organization And Nature Of Operations [Line Items]
Number of shares sold to advisor | shares				110
Smartstop Storage Advisors LLC.
Organization And Nature Of Operations [Line Items]
Investment by affiliate in exchange for additional limited partnership interests			$ 1,000
Smartstop OP L P [Member]
Organization And Nature Of Operations [Line Items]
Equity ownership percentage					5.00%
Advisor purchased a limited partnership interest in Operating Partnership, number of partnership units | shares		549,451
Initial capital contribution		$ 5,000,000.0
SmartStop REIT Advisors, LLC | Strategic Storage Advisor IV, LLC
Organization And Nature Of Operations [Line Items]
Percentage of economic interests owned by sponsor					90.00%
Percentage of voting membership interests owned by sponsor					100.00%
SmartStop REIT Advisors, LLC | Strategic Storage Property Management VI, LLC
Organization And Nature Of Operations [Line Items]
Percentage of Property Management owned by sponsor					100.00%