Significant Accounting Policies (Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization	$ (88)	$ (98)
Indefinite-lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	8	4
Long-term intangible assets
Gross Carrying Value	254	275
Accumulated Amortization	(88)	(98)
Net Carrying Value	166	177
Renewable energy credits
Indefinite-lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	2	2
Carbon offsets
Indefinite-lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	6	2
Contract intangibles
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	246	271
Accumulated Amortization	(88)	(98)
Net Carrying Value	158	173
Long-term intangible assets
Accumulated Amortization	(88)	$ (98)
Contract intangibles | DTE Vantage
Finite-Lived Intangible Assets [Line Items]
Write-off of fully amortized assets, gross carrying value	25
Write-off of fully amortized assets, accumulated amortization	$ 25
Contract intangibles | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Lives	12 years
Contract intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Lives	26 years