CONSOLIDATED STATEMENTS OF CHANGES IN PARTNERS' CAPITAL - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Partners’ Capital Excluding Noncontrolling Interests	Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjustment	Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjusted Balance	Noncontrolling Interests	Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjustment	Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjusted Balance	Series B Preferred Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests	Series B Preferred Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjustment	Series B Preferred Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjusted Balance	Common Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests	Common Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjustment	Common Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjusted Balance	Series A Preferred Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests	Series A Preferred Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjustment	Series A Preferred Units Limited Partners Partners’ Capital Excluding Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjusted Balance
Balance, beginning of period at Dec. 31, 2017	$ 10,958	$ 113	$ 11,071	$ 10,958	$ 113	$ 11,071	$ 0	$ 0	$ 0	$ 788	$ 0	$ 788	$ 8,665	$ 113	$ 8,778	$ 1,505	$ 0	$ 1,505
Increase (Decrease) in Partners' Capital [Roll Forward]
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201705Member
Net income/(loss)	$ 2,216			2,216			0			49			2,018			149
Distributions (Note 12)	(1,069)			(1,069)			0			(49)			(871)			(149)
Other comprehensive income/(loss)	(260)			(260)			0			0			(260)			0
Equity-indexed compensation expense	56			56			0			0			56			0
Other	(12)			(12)			0			(1)			(11)			0
Balance, end of period at Dec. 31, 2018	12,002			12,002			0			787			9,710			1,505
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income/(loss)	2,180			2,171			9			49			1,973			149
Distributions (Note 12)	(1,208)			(1,202)			(6)			(49)			(1,004)			(149)
Other comprehensive income/(loss)	97			97			0			0			97			0
Equity-indexed compensation expense	17			17			0			0			17			0
Sale of noncontrolling interest in a subsidiary (Note 12)	128			(2)			130			0			(2)			0
Other	(21)			(21)			0			0			(21)			0
Balance, end of period at Dec. 31, 2019	13,195			13,062			133			787			10,770			1,505
Increase (Decrease) in Partners' Capital [Roll Forward]
Net income/(loss)	(2,580)			(2,590)			10			49			(2,788)			149
Distributions (Note 12)	(863)			(853)			(10)			(49)			(655)			(149)
Other comprehensive income/(loss)	15			15			0			0			15			0
Equity-indexed compensation expense	19			19			0			0			19			0
Repurchase of common units (Note 12)	(50)			(50)			0			0			(50)			0
Contributions from noncontrolling interests (Note 12)	12			0			12			0			0			0
Other	(10)			(10)			0			0			(10)			0
Balance, end of period at Dec. 31, 2020	$ 9,738			$ 9,593			$ 145			$ 787			$ 7,301			$ 1,505