Organization - Additional Information (Detail)						9 Months Ended
	Apr. 08, 2016 $ / shares	Oct. 01, 2015 USD ($) $ / shares	Aug. 31, 2014	May 23, 2014 USD ($)	Aug. 02, 2013 USD ($) shares	Sep. 30, 2016 USD ($) Property $ / shares shares	Apr. 21, 2016 $ / shares	Apr. 14, 2016 $ / shares	Dec. 31, 2015 $ / shares shares
Organization and Nature of Operations [Line Items]
Date of formation of company						Jan. 08, 2013
Preferred Stock, shares authorized | shares						200,000,000			200,000,000
Preferred Stock, par value | $ / shares						$ 0.001			$ 0.001
Shares issuable pursuant to distribution reinvestment plan						$ 95,000,000
Sale of common shares						$ 257,582,567
Number of self storage facilities | Property						66
Percentage of non-voting equity owned			15.00%
Primary Offering | Maximum
Organization and Nature of Operations [Line Items]
Common stock, value authorized						$ 1,000,000,000
Primary Offering | Minimum
Organization and Nature of Operations [Line Items]
Sale of common shares				$ 1,500,000
Investments in Majority-owned Subsidiaries | Affiliate
Organization and Nature of Operations [Line Items]
Percentage owned by affiliate						2.50%
Class A Common stock
Organization and Nature of Operations [Line Items]
Common Stock, shares authorized | shares						350,000,000			350,000,000
Common stock, par value | $ / shares						$ 0.001			$ 0.001
Estimated value per common share | $ / shares	$ 10.09
Offering price per share | $ / shares						$ 10.00		$ 11.21
Class A Common stock | Distribution Reinvestment Plan
Organization and Nature of Operations [Line Items]
Selling price per share | $ / shares							$ 10.09
Class T Common stock
Organization and Nature of Operations [Line Items]
Common Stock, shares authorized | shares						350,000,000			350,000,000
Common stock, par value | $ / shares						$ 0.001			$ 0.001
Estimated value per common share | $ / shares	$ 10.09
Offering price per share | $ / shares						$ 9.47		$ 10.62
Class T Common stock | Distribution Reinvestment Plan
Organization and Nature of Operations [Line Items]
Selling price per share | $ / shares							$ 10.09
Common Stock | Class A Common stock
Organization and Nature of Operations [Line Items]
Sale of common shares						$ 20,962
Number of common stock issued | shares						20,962,269
Gross proceeds from issuance of common stock						$ 427,000,000
Common Stock | Class T Common stock
Organization and Nature of Operations [Line Items]
Sale of common shares						$ 4,298
Number of common stock issued | shares						4,298,459
Gross proceeds from issuance of common stock						$ 49,000,000
SSTI Preferred Investor
Organization and Nature of Operations [Line Items]
Number of Preferred Units received in the Operating Partnership | shares						2,400,000
Preferred equity investment						$ 59,500,000
Dealer Manager | President
Organization and Nature of Operations [Line Items]
Percentage of non-voting equity owned						15.00%
SmartStop Asset Management
Organization and Nature of Operations [Line Items]
Percentage of non-voting equity owned		15.00%
SmartStop Asset Management | President
Organization and Nature of Operations [Line Items]
Percentage of non-voting equity owned		15.00%
SmartStop Self Storage, Inc.
Organization and Nature of Operations [Line Items]
Sale price per share | $ / shares		$ 13.75
Enterprise value on sale		$ 1,400,000,000
SmartStop Self Storage, Inc. | Strategic Storage Trust Advisor II, LLC
Organization and Nature of Operations [Line Items]
Economic Interests			97.50%
Percentage of voting membership interest			100.00%
SmartStop Self Storage, Inc. | Property Management Agreement
Organization and Nature of Operations [Line Items]
Percentage of voting membership interest			100.00%
Strategic Storage Advisor II, LLC
Organization and Nature of Operations [Line Items]
Number of shares sold to advisor | shares					100
Sale of common shares to advisor					$ 1,000
Strategic Storage Operating Partnership II, L.P.
Organization and Nature of Operations [Line Items]
Date of formation of company						Jan. 09, 2013
Advisor purchased a limited partnership interest in Operating Partnership					200,000
Initial capital contribution					$ 1,000
Percentage of limited partnership interests						99.96%
Percentage of limited partnership interests owned by noncontrolling owners						0.04%