Leases (Future Minimum Lease Payments) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Operating Leases
2021	$ 37
2022	31
2023	22
2024	13
2025	8
2026 and thereafter	61
Total future minimum lease payments	172
Imputed interest	(28)
Lease liabilities	144
Finance Leases
2021	8
2022	8
2023	8
2024	2
2025	1
2026 and thereafter	7
Total future minimum lease payments	34
Imputed interest	(3)
Lease liabilities	31
DTE Electric
Operating Leases
2021	13
2022	12
2023	10
2024	8
2025	6
2026 and thereafter	32
Total future minimum lease payments	81
Imputed interest	(14)
Lease liabilities	67
Finance Leases
2021	6
2022	6
2023	6
2024	1
2025	0
2026 and thereafter	0
Total future minimum lease payments	19
Imputed interest	0
Lease liabilities	$ 19