Significant Accounting Policies (Cloud Computing Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Significant Accounting Policies [Line Items]
Amortization expense of capitalized cloud computing costs	$ 10	$ 4	$ 1
Gross value of capitalized cloud computing costs	56	42
Accumulated amortization of capitalized cloud computing costs	15	5
DTE Electric
Significant Accounting Policies [Line Items]
Amortization expense of capitalized cloud computing costs	8	3	$ 1
Gross value of capitalized cloud computing costs	44	33
Accumulated amortization of capitalized cloud computing costs	$ 12	$ 4