NONCONTROLLING INTERESTS - Operating Partnership Ownership (Details) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
	May. 14, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Operating Partnership Ownership
OP units issued (in shares)	20,408
Issuance of OP Units	$ 500
Additional consideration to be paid upon the completion of certain milestones within a specified period from closing	$ 1,500
Acrrued liability relating to the additional consideration to be paid in the acquisition of real property		$ 1,300
Increase to OP units owned by third parties and a corresponding decrease to capital		$ 6,073	$ 4,982
CubeSmart, L.P. and Subsidiaries
Operating Partnership Ownership
OP Units outstanding which are not owned by the general partner (as a percent)		1.20%		1.20%
OP units outstanding (in shares)		2,159,650		2,159,650
Number of trading days used to determine average of the closing prices of the common shares		10 days
Increase to OP units owned by third parties and a corresponding decrease to capital		$ 6,073	$ 4,982	$ 19,600