Acquisitions (Details) - USD ($) $ in Millions			3 Months Ended			6 Months Ended
		Jul. 01, 2021	Mar. 31, 2022		Mar. 31, 2021	Dec. 31, 2021
Business Acquisition [Line Items]
Revenues			$ 2,524		$ 2,612
Modified EBITDA Earnings Loss			1,393		1,410
Product [Member]
Business Acquisition [Line Items]
Revenues			1,104		1,147
Energy Commodities and Service
Business Acquisition [Line Items]
Revenues	[1]		(194)		(36)
Gain (Loss) on Derivative Instruments | Energy Related Derivative | Not Designated as Hedging Instrument [Member]
Business Acquisition [Line Items]
Unrealized Gain (Loss) on Derivatives			(125)	[2]	0
Gas & NGL Marketing Services | Product [Member]
Business Acquisition [Line Items]
Revenues	[3]		1,015		1,039
Gas & NGL Marketing Services | Energy Commodities and Service
Business Acquisition [Line Items]
Revenues	[1],[3]		(115)		(34)
Gas & NGL Marketing Services | Operating Segments [Member]
Business Acquisition [Line Items]
Revenues	[3]		854		1,055
Modified EBITDA Earnings Loss			13		93
Gas & NGL Marketing Services | Operating Segments [Member] | Product [Member]
Business Acquisition [Line Items]
Revenues	[3]		968		1,088
Gas & NGL Marketing Services | Gain (Loss) on Derivative Instruments | Energy Related Derivative | Not Designated as Hedging Instrument [Member]
Business Acquisition [Line Items]
Unrealized Gain (Loss) on Derivatives			$ (59)
Sequent Acquisition
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		100.00%
Business Combination, Consideration Transferred		$ 159
Business Combination, Working Capital Acquired		109
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents		8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables		498
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory		121
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other		4
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment		5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		306
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets		3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets		1,051
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable		514
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other		46
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other		1
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities		892
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net		$ 159
Sequent Acquisition | Minimum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		1 year
Sequent Acquisition | Maximum [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		8 years
Sequent Acquisition | Derivative
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other		$ 57
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets		49
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other		116
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other		$ 215
Sequent Acquisition | Gas & NGL Marketing Services | Energy Commodities and Service
Business Acquisition [Line Items]
Revenues						$ (43)
Sequent Acquisition | Gas & NGL Marketing Services | Operating Segments [Member]
Business Acquisition [Line Items]
Modified EBITDA Earnings Loss						(112)
Sequent Acquisition | Gas & NGL Marketing Services | Operating Segments [Member] | Product [Member]
Business Acquisition [Line Items]
Revenues						(43)
Affiliate Costs						80
Sequent Acquisition | Gas & NGL Marketing Services | Gain (Loss) on Derivative Instruments | Energy Related Derivative | Not Designated as Hedging Instrument [Member]
Business Acquisition [Line Items]
Unrealized Gain (Loss) on Derivatives						(109)
Sequent Acquisition | Gas & NGL Marketing Services | Selling, general, and administrative expenses [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs						$ 5
Sequent Acquisition | Pro Forma
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue					2,910
Business Acquisition, Pro Forma Net Income (Loss)					$ 547

[1] We record transactions that qualify as derivatives at fair value with changes in fair value recognized in earnings in the period of change and characterized as unrealized gains or losses. Gains and losses on derivatives held for energy trading purposes are presented on a net basis in revenue.

[2] Amounts for the three months ended March 31, 2022 include $59 million related to our Gas & NGL Marketing Services segment and $66 million related to our Other segment.

[3] See Note 1 – General, Description of Business, and Basis of Presentation.