SUBSEQUENT EVENTS (Details) - $ / shares	1 Months Ended
	Aug. 31, 2016	May 31, 2016
Subsequent events
Quarterly distribution declared (in dollars per common unit)		$ 0.28
Subsequent event
Subsequent events
Quarterly distribution declared (in dollars per common unit)	$ 0.28
Quarterly distribution declared (in dollars per preferred unit)	$ 0.544444