Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	$ 1,492	$ 1,320
DTE Electric
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	1,492	1,320
DTE Electric | Nuclear decommissioning trusts
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	1,492	1,320
DTE Electric | Nuclear decommissioning trusts | Fermi 2
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	1,475	1,291
DTE Electric | Nuclear decommissioning trusts | Fermi 1
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Nuclear decommissioning trusts | Low-level radioactive waste
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	$ 14	$ 26