Significant Accounting Policies (Income Taxes) (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Schedule of Income Taxes [Line Items]
Statutory federal income tax rate	21.00%	21.00%
Increase (decrease) due to:
State and local income taxes, net of federal benefit	4.40%	4.40%
Production tax credits	(6.20%)	(7.50%)
TCJA amortization	(4.10%)	(12.40%)
Investment tax credits	(2.30%)	(0.20%)
Enactment of West Virginia income tax legislation, net of federal benefit	(1.20%)	0.00%
Other	(1.50%)	(1.50%)
Effective Tax Rate	10.10%	3.80%
DTE Electric
Schedule of Income Taxes [Line Items]
Statutory federal income tax rate	21.00%	21.00%
Increase (decrease) due to:
State and local income taxes, net of federal benefit	5.60%	5.80%
Production tax credits	(7.10%)	(8.90%)
TCJA amortization	(4.50%)	(15.50%)
Other	(0.80%)	(0.90%)
Effective Tax Rate	14.20%	1.50%