Partnership Distributions - Narrative (Details) - $ / shares					3 Months Ended												12 Months Ended
	Jan. 23, 2020	May 14, 2019	Apr. 25, 2019	Sep. 30, 2016	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2019
Distribution Made to Limited Partner [Line Items]
Partner distribution period																	45 days
Distribution per limited partner unit (in dollars per share)			$ 0.6132		$ 0.6716	$ 0.6418	$ 0.6132	$ 0.5858	$ 0.5597	$ 0.5348	$ 0.5110	$ 0.4883	$ 0.4665	$ 0.4457	$ 0.4108	$ 0.4333
Common Units
Distribution Made to Limited Partner [Line Items]
Distribution per limited partner unit (in dollars per share)				$ 0.0408												$ 0.3925
Common Units | Subsequent Event
Distribution Made to Limited Partner [Line Items]
Distribution per limited partner unit (in dollars per share)	$ 0.6878
Limited Partner | Subordinated Units
Distribution Made to Limited Partner [Line Items]
Partners' capital account, units, converted		15,902,584