Significant Accounting Policies (Roll-Forward of Activity for Financing Receivables Credit Loss Reserves) (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 79	$ 92
Current period provision	44	49
Write-offs charged against allowance	(78)	(107)
Recoveries of amounts previously written off	31	45
Ending balance	76	79
DTE Electric
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	49	54
Current period provision	28	33
Write-offs charged against allowance	(51)	(66)
Recoveries of amounts previously written off	20	28
Ending balance	46	49
Trade accounts receivable
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	78	89
Current period provision	44	49
Write-offs charged against allowance	(78)	(105)
Recoveries of amounts previously written off	31	45
Ending balance	75	78
Other receivables
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	1	3
Current period provision	0	0
Write-offs charged against allowance	0	(2)
Recoveries of amounts previously written off	0	0
Ending balance	$ 1	$ 1