v3.25.3
Summary of Significant Accounting Policies - Schedule of Computation of Earnings Per Common Share (Details) - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2025
Sep. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]        
Net income (loss) $ 5,548 $ (3,392) $ (4,706) $ (5,735)
Net (income) loss attributable to noncontrolling interests (321) 314 377 405
Net income (loss) attributable to SmartStop Self Storage REIT, Inc. 5,227 (3,078) (4,329) (5,330)
Less: Accretion - preferred equity costs 0 0 (3,644) 0
Less: Distributions to preferred stockholders 0 (3,142) (3,567) (9,358)
Less: Distributions to participating securities (171) (113) (458) (340)
Net income (loss) attributable to common stockholders - basic: 5,056 (6,333) (11,998) (15,028)
Net income (loss) attributable to common stockholders - diluted: $ 5,056 $ (6,333) $ (11,998) $ (15,028)
Weighted average number of shares outstanding- basic 55,097,961 24,119,247 44,625,950 24,173,519
Weighted average number of shares outstanding - diluted 55,345,663 24,119,247 44,625,950 24,173,519
Earnings Per Share, Basic $ 0.09 $ (0.26) $ (0.27) $ (0.62)
Earnings Per Share, Diluted $ 0.09 $ (0.26) $ (0.27) $ (0.62)
Unvested LTIP Units        
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]        
Equivalent Shares, included in computation of earnings per share as effect of antidilutive 0 0 0 0
Unvested restricted stock awards        
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]        
Equivalent Shares, included in computation of earnings per share as effect of antidilutive 247,702 0 0 0