SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Measurement period adjustments	$ 0	$ 0
Loan procurement costs, net of amortization	2,313		$ 2,800
Accounting Standards Update 2015-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Measurement period adjustments	0
Accounting Standards Update 2015-03 | Reclassifications
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loan procurement costs, net of amortization			(10,700)
Debt			(10,700)
CubeSmart, L.P. and Subsidiaries
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loan procurement costs, net of amortization	$ 2,313		$ 2,800