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, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
2017	$ 96
2018	101
2019	106
2020	110
2021	114
2022-2026	595
Total expected future benefit payments	1,122
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
2017	74
2018	79
2019	82
2020	85
2021	88
2022-2026	457
Total expected future benefit payments	$ 865