Revenue - Expenses Recognized for Estimated Uncollectible Accounts Receivable (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue from External Customer [Line Items]
Allowance for doubtful accounts receivable write-offs	$ 24	$ 31	$ 53	$ 56
DTE Electric
Revenue from External Customer [Line Items]
Allowance for doubtful accounts receivable write-offs	$ 14	$ 17	$ 30	$ 31