Revenue (Revenues Outside the Scope of Topic 606) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Leases	$ 68	$ 57	$ 132	$ 125
Electric
Disaggregation of Revenue [Line Items]
Other revenues	6	8	14	18
Gas
Disaggregation of Revenue [Line Items]
Other revenues	1	2	5	7
Alternative Revenue Program	0	0	0	2
DTE Vantage
Disaggregation of Revenue [Line Items]
Leases	26	26	70	74
Energy Trading
Disaggregation of Revenue [Line Items]
Derivatives	$ 1,324	$ 731	$ 3,377	$ 1,835