Significant Accounting Policies (Uncollectible Expense) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 12	$ 7	$ 46	$ 42
DTE Electric
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 12	$ 10	$ 28	$ 26