Impairments Goodwill Impairments (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill, Balance		$ 21,451		$ 21,451
Goodwill impairment loss				(1,600)
Goodwill, Balance	$ 19,851			19,851
Regulated
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill, Balance		14,249		14,249
Goodwill impairment loss				0
Goodwill, Balance	14,249			14,249
Natural Gas Pipelines Non-Regulated
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill, Balance		3,343		3,343
Goodwill impairment loss	(1,000)			(1,000)
Goodwill, Balance	2,343			2,343
CO2
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill, Balance		1,528		1,528
Goodwill impairment loss		(600)		(600)
Goodwill, Balance	$ 928			$ 928
CO2 | Maximum
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	10.00%			10.00%
Products Pipelines Terminals
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill, Balance		151		$ 151
Goodwill impairment loss				0
Goodwill, Balance	$ 151			151
Terminals
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill, Balance		802		802
Goodwill impairment loss				0
Goodwill, Balance	$ 802			$ 802
Terminals | Maximum
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	10.00%			10.00%
Products Pipelines
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill, Balance		$ 1,378		$ 1,378
Goodwill impairment loss				0
Goodwill, Balance	$ 1,378			$ 1,378
Products Pipelines | Maximum
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount	10.00%			10.00%
CO2
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Goodwill impairment loss	$ 0		$ 0	$ (600)	$ 0
Valuation Technique, Discounted Cash Flow | Natural Gas Pipelines Non-Regulated
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Number of Years of Projection to Determine Fair Value				6 years 6 months
Estimated Weighted Average Cost Of Capital	8.00%			8.00%
Valuation Technique, Discounted Cash Flow | CO2
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Estimated Weighted Average Cost Of Capital		9.25%
Valuation Technique, Discounted Cash Flow | Oil and Gas Properties | CO2
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Estimated Weighted Average Cost Of Capital		10.50%
Valuation, Market Approach | Natural Gas Pipelines Non-Regulated
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Fair Value Measurement Inputs and Valuation Techniques, Weighting Of Approach	0.25			0.25
Enterprise Value to EBITDA Multiple Valuation	10			10
Valuation, Income Approach | Natural Gas Pipelines Non-Regulated
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Fair Value Measurement Inputs and Valuation Techniques, Weighting Of Approach	0.75			0.75
Weighted Market Approach and Income Approach | Natural Gas Pipelines Non-Regulated
Impairment of Goodwill, Long-lived assets and equity investments [Line Items]
Enterprise Value to EBITDA Multiple Valuation	11			11