Reportable Segments Other expense (income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Other (income) expense(d)	$ (945)	$ 164	$ 12
Operating Segments | Natural Gas Pipelines
Segment Reporting Information [Line Items]
Other (income) expense(d)	(680)	629	26
Operating Segments | Products Pipelines
Segment Reporting Information [Line Items]
Other (income) expense(d)	0	(2)	0
Operating Segments | Terminals
Segment Reporting Information [Line Items]
Other (income) expense(d)	(342)	54	(14)
Operating Segments | CO2
Segment Reporting Information [Line Items]
Other (income) expense(d)	77	79	(1)
Operating Segments | Kinder Morgan Canada
Segment Reporting Information [Line Items]
Other (income) expense(d)	2	(596)	0
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Other (income) expense(d)	$ (2)	$ 0	$ 1