Units Outstanding (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Units Outstanding
Outstanding as of December 31, 2019 (in units)	270,380,314
Options exercised (in units)	5,182	300,000
Units issued (in units)	344,698
Units purchased and retired (in units)	748,763
Balance as of March 31, 2020 (in units)	269,981,431