Significant Accounting Policies (Uncollectible Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 70	$ 74	$ 55
DTE Electric
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 45	$ 50	$ 38