Retirement Benefits and Trusteed Assets (OPEB - Benefits related to Qualified and Nonqualified Pension Plans Expected to be paid in the Next Ten Years) (Details) - Other postretirement benefit plan $ in Millions	Dec. 31, 2019 USD ($)
Defined Benefit Plan Disclosure [Line Items]
2020	$ 84
2021	88
2022	92
2023	94
2024	96
2025-2029	496
Total	950
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
2020	64
2021	67
2022	70
2023	72
2024	73
2025-2029	378
Total	$ 724