Losses and Gains on Divestitures, Impairments and Other Write-downs – Schedule of Pre-tax Loss (Gain) on Impairments and Divestitures (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Impairment of goodwill					$ 1,600
Gain on sale of interests in NGPL Holdings LLC				$ (206)	0
Loss (gain) on divestitures of long-lived assets and other write-downs	$ 4		$ 11	1,602	1,987
Pre-tax loss on impairments, divestitures and other write-downs, net	4		11	1,513	1,987
Corporate and intersegment eliminations
Finite-Lived Intangible Assets [Line Items]
Other loss (gain) on divestitures of long-lived assets, net	1		0	(3)	0
Natural Gas Pipelines
Finite-Lived Intangible Assets [Line Items]
Impairments of long-lived and intangible assets	0		0	1,600	0
Impairment of goodwill	0		0	0	1,000
Loss (gain) on divestitures of long-lived assets and other write-downs	$ 0		11	$ (1)	11
Natural Gas Pipelines | Valuation Technique, Discounted Cash Flow
Finite-Lived Intangible Assets [Line Items]
Estimated Weighted Average Cost Of Capital	8.50%			8.50%
Natural Gas Pipelines | NGPL Holdings, LLC
Finite-Lived Intangible Assets [Line Items]
Gain on sale of interests in NGPL Holdings LLC	$ 0		0	$ (206)	0
Natural Gas Pipelines | Ruby Pipeline Holding Company LLC
Finite-Lived Intangible Assets [Line Items]
Loss on write-down of related party note receivable	0	$ 117	0	117	0
Products Pipelines
Finite-Lived Intangible Assets [Line Items]
Impairments of long-lived and intangible assets	0		0	0	21
Terminals
Finite-Lived Intangible Assets [Line Items]
Impairment of long-lived and intangible assets	14		0	14	5
CO2
Finite-Lived Intangible Assets [Line Items]
Impairments of long-lived and intangible assets	0		0	0	350
Impairment of goodwill	0		0	0	600
Loss (gain) on divestitures of long-lived assets and other write-downs	$ (11)		$ 0	$ (8)	$ 0