PARTNERS' CAPITAL (Details)				3 Months Ended									12 Months Ended
	Mar. 09, 2020	Jan. 03, 2012	Jan. 03, 2012	Mar. 31, 2021 $ / item	Dec. 31, 2020 $ / item	Sep. 30, 2020 $ / item	Jun. 30, 2020 $ / item	Mar. 31, 2020 $ / item	Dec. 31, 2019 $ / item	Sep. 30, 2019 $ / item	Jun. 30, 2019 $ / item	Mar. 31, 2019 $ / item	Dec. 31, 2020 USD ($) item $ / item	Dec. 31, 2019 USD ($) $ / item
Depositary receipts exchange ratio for Class A units | item													30
Total distribution per unit (in dollars per unit)					38.40				38.40				38.40	38.40
Total distribution per depository receipt (in dollars per receipt)					1.28				1.28				1.28	1.28
Total distributions | $													$ 4,675,754	$ 4,696,893
Earnings per depository receipt
Net Income per Depositary Receipt (in dollars per receipt)					(0.27)	(0.12)	0.40	0.37	0.51	0.38	0.48	0.41	0.39	1.78
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%												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)													0.39	1.78
Distributions per Depositary Receipt (in dollars per share)					1.28				1.28				1.28	1.28
Class B
Fixed distribution percentage of unit holders													19.00%