Derivatives and Risk Management Activities - Fair Value (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Level 3
Rollforward of Level 3 Net Asset/(Liability)
Beginning Balance	$ (29)	$ (51)
Net gains/(losses) for the period included in earnings	15	12
Settlements	12	10
Ending Balance	(2)	(29)
Change in unrealized gains/(losses) included in earnings relating to Level 3 derivatives still held at the end of the period	15	12
Recurring Fair Value Measures
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(78)	(267)
Recurring Fair Value Measures \| Commodity Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(143)	(301)
Recurring Fair Value Measures \| Interest Rate Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	65	46
Recurring Fair Value Measures \| Preferred Distribution Rate Reset Option
Recurring Fair Value Measurements
Total net derivative asset/(liability)		(12)
Recurring Fair Value Measures \| Level 1
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(17)	(143)
Recurring Fair Value Measures \| Level 1 \| Commodity Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(17)	(143)
Recurring Fair Value Measures \| Level 1 \| Interest Rate Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	0	0
Recurring Fair Value Measures \| Level 1 \| Preferred Distribution Rate Reset Option
Recurring Fair Value Measurements
Total net derivative asset/(liability)	0	0
Recurring Fair Value Measures \| Level 2
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(59)	(95)
Recurring Fair Value Measures \| Level 2 \| Commodity Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(124)	(143)
Recurring Fair Value Measures \| Level 2 \| Interest Rate Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	65	46
Recurring Fair Value Measures \| Level 2 \| Preferred Distribution Rate Reset Option
Recurring Fair Value Measurements
Total net derivative asset/(liability)	0	2
Recurring Fair Value Measures \| Level 3
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(2)	(29)
Recurring Fair Value Measures \| Level 3 \| Commodity Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	(2)	(15)
Recurring Fair Value Measures \| Level 3 \| Interest Rate Derivatives
Recurring Fair Value Measurements
Total net derivative asset/(liability)	0	0
Recurring Fair Value Measures \| Level 3 \| Preferred Distribution Rate Reset Option
Recurring Fair Value Measurements
Total net derivative asset/(liability)	$ 0	$ (14)

Fair value of the assets less the liabilities of a derivative or group of derivatives.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

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Amount of unrealized gain (loss) recognized in income for derivative asset (liability) after deduction of derivative liability (asset), measured at fair value using unobservable input (level 3) and still held.

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Amount of gain (loss) recognized in income from derivative asset (liability) after deduction of derivative liability (asset), measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of settlements of financial instrument classified as a derivative asset (liability) after deduction of derivative liability, measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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Fair value of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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