Property, Plant and Equipment Classes and Depreciation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 16,950	$ 15,359
Property, Plant and Equipment, Net, Excluding Nondepreciable Assets	34,057	34,207
Property, plant and equipment, net	36,419	37,897
Depreciation, Depletion and Amortization, Property, Plant and Equipment	2,176	2,057	$ 2,022
Pipelines
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	19,856	19,727
Equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	25,791	24,392
Other
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	5,360	5,447
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,356	1,378
Construction work in progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,006	2,312
Natural Gas Pipelines Regulated
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 12,229	$ 12,349