UNSECURED SENIOR NOTES (Details)
$ in Thousands
9 Months Ended
Apr. 04, 2017
USD ($)
Oct. 26, 2015
USD ($)
Dec. 17, 2013
USD ($)
Sep. 30, 2017
USD ($)
Dec. 31, 2016
USD ($)
Mortgage loans and Notes payable          
Less: Loan procurement costs, net       $ (1,709) $ (2,150)
Total unsecured senior notes, net       1,142,194 1,039,076
CubeSmart, L.P. and Subsidiaries          
Mortgage loans and Notes payable          
Less: Loan procurement costs, net       (1,709) (2,150)
Total unsecured senior notes, net       1,142,194 1,039,076
Senior Notes          
Mortgage loans and Notes payable          
Carrying value       1,150,000 1,050,000
Less: Discount on issuance of notes, net       (630) (3,971)
Less: Loan procurement costs, net       (7,176) (6,953)
Total unsecured senior notes, net       $ 1,142,194 1,039,076
Senior Notes | Maximum          
Mortgage loans and Notes payable          
Consolidated leverage ratio       0.60  
Secured debt leverage ratio       0.40  
Senior Notes | Minimum          
Mortgage loans and Notes payable          
Consolidated interest coverage ratio       1.50  
Financial and customary covenant, minimum unencumbered asset (as a percent)       150.00%  
Senior notes 4.800% due 2022          
Mortgage loans and Notes payable          
Senior notes, principal amount       $ 250,000  
Interest rate (as a percent)       4.80%  
Carrying value       $ 250,000 250,000
Effective interest rate (as a percent)       4.82%  
Senior notes 4.375% due 2023          
Mortgage loans and Notes payable          
Senior notes, principal amount       $ 300,000  
Interest rate (as a percent) 4.375%   4.375% 4.375%  
Carrying value       $ 300,000 250,000
Effective interest rate (as a percent) 3.495%   4.501% 4.33%  
Effective weighted average interest rate (as a percent)       4.33%  
Proceeds from senior notes $ 50,000   $ 250,000    
Debt instrument, redemption percentage 105.04%   98.995%    
Senior notes 4.000% due 2025          
Mortgage loans and Notes payable          
Senior notes, principal amount       $ 300,000  
Interest rate (as a percent) 4.00% 4.00%   4.00%  
Carrying value       $ 300,000 250,000
Effective interest rate (as a percent) 3.811% 4.032%   3.99%  
Effective weighted average interest rate (as a percent)       3.994%  
Proceeds from senior notes $ 50,000 $ 250,000      
Debt instrument, redemption percentage 101.343% 99.735%      
Senior Notes 3.125% Due 2026          
Mortgage loans and Notes payable          
Senior notes, principal amount       $ 300,000  
Interest rate (as a percent)       3.125%  
Carrying value       $ 300,000 300,000
Effective interest rate (as a percent)       3.18%  
Credit Facility          
Mortgage loans and Notes payable          
Less: Loan procurement costs, net       $ (705) $ (1,251)
Effective weighted average interest rate (as a percent)       2.82%