Significant Accounting Policies (Cloud Computing Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Significant Accounting Policies [Line Items]
Amortization expense of capitalized cloud computing costs	$ 12	$ 10	$ 4
Gross value of capitalized cloud computing costs	64	56
Accumulated amortization of capitalized cloud computing costs	27	15
DTE Electric
Significant Accounting Policies [Line Items]
Amortization expense of capitalized cloud computing costs	10	8	$ 3
Gross value of capitalized cloud computing costs	51	44
Accumulated amortization of capitalized cloud computing costs	$ 22	$ 12