Cash distributions and earnings per unit - Schedule Of Incentive Distributions Made To General Partners Or Unitholders By Distribution (Details)	12 Months Ended
	Dec. 31, 2020 $ / shares
Minimum Quarterly Distribution | Incentive Distribution Right Holder
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	0.00%
First Target Distribution | Incentive Distribution Right Holder
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	0.00%
Second Target Distribution | Incentive Distribution Right Holder
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	13.00%
Third Target Distribution | Incentive Distribution Right Holder
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	23.00%
Thereafter | Incentive Distribution Right Holder
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	48.00%
Total Quarterly Distribution Target Amount | Minimum Quarterly Distribution
Schedule of Capitalization, Equity [Line Items]
Distribution Per Unit	$ 5.25
Total Quarterly Distribution Target Amount | First Target Distribution
Schedule of Capitalization, Equity [Line Items]
Distribution Per Unit	6.0375
Total Quarterly Distribution Target Amount | Second Target Distribution | Minimum [Member]
Schedule of Capitalization, Equity [Line Items]
Distribution Per Unit	6.0375
Total Quarterly Distribution Target Amount | Second Target Distribution | Maximum [Member]
Schedule of Capitalization, Equity [Line Items]
Distribution Per Unit	6.5625
Total Quarterly Distribution Target Amount | Third Target Distribution | Minimum [Member]
Schedule of Capitalization, Equity [Line Items]
Distribution Per Unit	6.5625
Total Quarterly Distribution Target Amount | Third Target Distribution | Maximum [Member]
Schedule of Capitalization, Equity [Line Items]
Distribution Per Unit	7.875
Total Quarterly Distribution Target Amount | Thereafter
Schedule of Capitalization, Equity [Line Items]
Distribution Per Unit	$ 7.875
Limited Partner [Member] | Minimum Quarterly Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	98.00%
Limited Partner [Member] | First Target Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	98.00%
Limited Partner [Member] | Second Target Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	85.00%
Limited Partner [Member] | Third Target Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	75.00%
Limited Partner [Member] | Thereafter
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	50.00%
General Partner [Member] | Minimum Quarterly Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	2.00%
General Partner [Member] | First Target Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	2.00%
General Partner [Member] | Second Target Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	2.00%
General Partner [Member] | Third Target Distribution
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	2.00%
General Partner [Member] | Thereafter
Schedule of Capitalization, Equity [Line Items]
Percentage allocations of the additional available cash	2.00%