Units Outstanding (Details) - shares	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Units Outstanding
Outstanding as of December 31, 2019 (in units)	270,380,314
Options exercised (in units)	5,182	400,000
Units issued (in units)	408,059
Units purchased and retired (in units)	(2,173,368)
Balance as of June 30, 2020 (in units)	268,620,187