Net Income Per Limited Partner Unit - Schedule of Allocation of Net Income to Arrive at Net Income Per Limited Partner Unit (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Limited Partners Capital Account [Line Items]
Net income	$ 142	$ 137
Less: Net income attributable to noncontrolling interests	4	5
Net income attributable to the Partnership	138	132
Distributions declared	162	119
Income (less than) / in excess of distributions	(24)	13
General Partner
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership	55	27
Distributions declared	55	26
Income (less than) / in excess of distributions	0	1
Limited Partners’ Common Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership	83	105
Distributions declared	107	93
Income (less than) / in excess of distributions	$ (24)	$ 12