SUBSEQUENT EVENTS (Details) - Subsequent event	1 Months Ended
	Jul. 31, 2018 USD ($) $ / shares
Subsequent events
Quarterly distribution declared (in dollars per unit)	$ 0.28
Preferred equity quarterly distribution (in dollars per unit)	$ 0.4375
Preferred Shares
Subsequent events
Authorized amount in preferred share buyback | $	$ 50,000,000.0