PARTNERS' CAPITAL (Details)			1 Months Ended	3 Months Ended								12 Months Ended
	Jan. 03, 2012	Jan. 03, 2012	Jan. 31, 2020 $ / item	Dec. 31, 2019 $ / item	Sep. 30, 2019 $ / item	Jun. 30, 2019 $ / item	Mar. 31, 2019 $ / item	Dec. 31, 2018 $ / item	Sep. 30, 2018 $ / item	Jun. 30, 2018 $ / item	Mar. 31, 2018 $ / item	Dec. 31, 2019 item $ / item	Dec. 31, 2018 $ / item
Quarterly distributions per depositary receipt (in dollars per receipt)				0.32				0.30				0.32	0.30
Quarterly distribution per unit (in dollars per unit)				9.60				9.00				9.60	9.00
Earnings per depository receipt
Net Income per Depositary Receipt (in dollars per receipt)				0.51	0.38	0.48	0.41	0.43	0.18	0.01	0.50	1.78	1.12
Subsequent event
Quarterly distribution per unit approved (in dollars per unit)			9.60
Quarterly distributions per depositary receipt (in dollars per receipt)			(0.32)
Limited Partner
Number of classes of partners | item												2
General Partnership
Number of classes of partners | item												1
Fixed distribution percentage of unit holders												1.00%
Class A
Fixed distribution percentage of unit holders												80.00%
Class B
Fixed distribution percentage of unit holders												19.00%
Class A
Forward split of depositary receipts	3	3
Exchange ratio of depositary receipts for partnership units before adjustment	10	10
Exchange ratio of depositary receipts for partnership units after adjustment	30	30
Number of units in each depository receipt	0.03333	0.03333
Earnings per depository receipt
Net Income per Depositary Receipt (in dollars per receipt)												1.78	1.12
Distributions per Depositary Receipt (in dollars per share)				1.28				1.20				1.28	1.20
Class B
Fixed distribution percentage of unit holders												19.00%