Significant Accounting Policies (Cloud Computing Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Significant Accounting Policies [Line Items]
Amortization expense of capitalized cloud computing costs	$ 13	$ 12	$ 10
Gross value of capitalized cloud computing costs	94	64
Accumulated amortization of capitalized cloud computing costs	40	27
DTE Electric
Significant Accounting Policies [Line Items]
Amortization expense of capitalized cloud computing costs	10	10	$ 8
Gross value of capitalized cloud computing costs	69	51
Accumulated amortization of capitalized cloud computing costs	$ 32	$ 22