Revenue (Expenses Recognized for Estimated Uncollectible Accounts Receivable) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue from External Customer [Line Items]
Expenses recognized for estimated uncollectible accounts receivable	$ 111	$ 140
DTE Electric
Revenue from External Customer [Line Items]
Expenses recognized for estimated uncollectible accounts receivable	$ 65	$ 85