Leases (Future Minimum Lease Payments - Topic 842) (Details) $ in Millions	Mar. 31, 2019 USD ($)
Operating Leases
2019	$ 28
2020	30
2021	22
2022	16
2023	13
2024 and thereafter	50
Total future minimum lease payments	159
Imputed interest	(28)
Total	131
Finance Leases
2019	3
2020	4
2021	3
2022	0
2023	0
2024 and thereafter	0
Total future minimum lease payments	10
Imputed interest	0
Total	10
DTE Electric
Operating Leases
2019	12
2020	12
2021	11
2022	7
2023	6
2024 and thereafter	30
Total future minimum lease payments	78
Imputed interest	(14)
Total	64
Finance Leases
2019	3
2020	4
2021	3
2022	0
2023	0
2024 and thereafter	0
Total future minimum lease payments	10
Imputed interest	0
Total	$ 10