Significant Accounting Policies (Uncollectible Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 27	$ 10	$ 65	$ 45
DTE Electric
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 22	$ 11	$ 43	$ 28