v3.25.4
Summary of Significant Accounting Policies - Schedule of Computation of Earnings Per Common Share (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]      
Net (loss) income $ (1,737) $ (5,887) $ 11,647
Net loss (income) attributable to noncontrolling interests 190 266 (1,893)
Net income (loss) attributable to SmartStop Self Storage REIT, Inc. (1,547) (5,621) 9,754
Less: Distributions to preferred stockholders (3,567) (12,758) (12,500)
Less: Accretion- preferred equity costs (3,644) 0 0
Less: Distributions to participating securities (628) (451) (369)
Net loss attributable to common stockholders for basic computations: (9,386) (18,830) (3,115)
Net loss attributable to common stockholders for diluted computations: $ (9,386) $ (18,830) $ (3,115)
Class A and T Common Stock      
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]      
Weighted average common shares outstanding - basic 47,299,813 24,139,414 24,201,985
Weighted average common shares outstanding - diluted 47,299,813 24,139,414 24,201,985
Net loss per Common Stock, Basic $ (0.2) $ (0.78) $ (0.13)
Net loss per Common Stock, Diluted $ (0.2) $ (0.78) $ (0.13)
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
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 0 0 0