Earnings Per Limited Partner Unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income		$ 105	$ 123
Net (loss) income attributable to noncontrolling interest		(7)	1
Series A Preferred Unit distributions		9	9
General partner interest in net income		0	0
Net Income Attributable to Common Units (Note 5)		103	$ 113
Phantom units
Basic weighted average number of outstanding
Basic weighted average number of outstanding	[1]		1,000,000
Common Units
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income Attributable to Common Units (Note 5)		103	$ 113
Dilutive effect of Series A Preferred Unit distributions		9	0
Diluted net income		$ 112	$ 113
Basic weighted average number of outstanding
Basic weighted average number of outstanding		437	435	[1]
Basic earnings per unit
Basic earnings per unit		$ 0.24	$ 0.26
Dilutive effect of Series A Preferred Units (in units)		144	0
Diluted weighted average number of outstanding units		581	435
Diluted earnings per unit		$ 0.19	$ 0.26
Performance Units and Phantom Units [Member]
Basic earnings per unit
Earnings Per Share, Diluted, Undistributed		$ 0.01	$ 0.01

[1] Basic weighted average number of outstanding common units includes approximately two million and one million time-based phantom units for the three months ended March 31, 2020 and 2019, respectively.