Net Income Per Limited Partner Unit - Schedule of Basic and Diluted Net Income Per Unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Distribution Made To Limited Partner [Line Items]
Distributions declared	$ 161	$ 131	$ 323	$ 250
Income (less than) / in excess of distributions	(32)	(16)	(56)	(3)
Net income attributable to the Partnership	141	115	279	247
Net income attributable to the Partnership's common unitholders (basic)	129		267
General Partner
Distribution Made To Limited Partner [Line Items]
Distributions declared	0	31	55	57
Income (less than) / in excess of distributions	0	(1)	0	0
Net income attributable to the Partnership		30		57
Net income attributable to the Partnership's common unitholders (basic)	0		55
Limited Partners’ Common Units
Distribution Made To Limited Partner [Line Items]
Distributions declared	161	100	268	193
Income (less than) / in excess of distributions	(32)	(15)	(56)	(3)
Net income attributable to the Partnership		$ 85		$ 190
Net income attributable to the Partnership's common unitholders (basic)	129		212
Dilutive effect of preferred units	12		12
Net income attributable to the Partnership's common unitholders (diluted)	$ 141		$ 224
Weighted average units outstanding (in millions)
Weighted average units outstanding - Basic (in shares)	393.3		313.3
Dilutive effect of preferred units (in shares)	50.8		25.4
Weighted average units outstanding - Diluted (in shares)	444.1		338.7
Weighted average units outstanding, basic and diluted (in shares)		226.4		225.1
Net income per Limited Partner Unit (in dollars)
Net income per Limited Partner Unit - basic (in dollars per share)	$ 0.33	$ 0.38	$ 0.68	$ 0.84
Net income per Limited Partner Unit - diluted (in dollars per share)	$ 0.32	0.38	$ 0.66	0.84
Net income per Limited Partner unit, basic and diluted (in dollars per share)		$ 0.38		$ 0.84