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				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Apr. 01, 2020
Limited Partners Capital Account [Line Items]
Net income	$ 144	$ 142	$ 119	$ 137	$ 286	$ 256
Less: Net income attributable to noncontrolling interests	3		4		7	9
Net income attributable to the Partnership	141		115		279	247
Distributions declared	161		131		323	250
Preferred unitholder’s interest in net income attributable to the Partnership	12		0		12	0
Income (less than) / in excess of distributions	(32)		(16)		(56)	(3)
General Partner
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership			30			57
Distributions declared	0		31		55	57
Income (less than) / in excess of distributions	0		(1)		0	0
General Partner | Economic Interest
Limited Partners Capital Account [Line Items]
Noncontrolling interest		2.00%					2.00%
Preferred Partner
Limited Partners Capital Account [Line Items]
Preferred unitholder’s interest in net income attributable to the Partnership	12		0		12	0
Limited Partners’ Common Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership			85			190
Distributions declared	161		100		268	193
Income (less than) / in excess of distributions	$ (32)		$ (15)		$ (56)	$ (3)