Leases (Future Minimum Lease Payments - Topic 842) (Details) $ in Millions	Sep. 30, 2019 USD ($)
Operating Leases
2019	$ 10
2020	35
2021	26
2022	19
2023	16
2024 and thereafter	62
Total future minimum lease payments	168
Imputed interest	(30)
Total	138
Finance Leases
2019	1
2020	4
2021	3
2022	0
2023	0
2024 and thereafter	0
Total future minimum lease payments	8
Imputed interest	0
Total	8
DTE Electric
Operating Leases
2019	4
2020	13
2021	11
2022	7
2023	6
2024 and thereafter	30
Total future minimum lease payments	71
Imputed interest	(13)
Total	58
Finance Leases
2019	1
2020	4
2021	3
2022	0
2023	0
2024 and thereafter	0
Total future minimum lease payments	8
Imputed interest	0
Total	$ 8