Significant Accounting Policies (Uncollectible Expense) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 4	$ 15	$ 35	$ 48
DTE Electric
Accounts, Notes, Loans and Financing Receivable [Line Items]
Uncollectible expense	$ 5	$ 9	$ 16	$ 26

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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