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, 2024	Dec. 31, 2023
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 63	$ 79
Current period provision	64	52
Write-offs charged against allowance	(77)	(112)
Recoveries of amounts previously written off	32	44
Ending balance	82	63
DTE Electric
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	41	49
Current period provision	42	36
Write-offs charged against allowance	(50)	(72)
Recoveries of amounts previously written off	20	28
Ending balance	53	41
Trade accounts receivable
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	62	78
Current period provision	64	52
Write-offs charged against allowance	(77)	(112)
Recoveries of amounts previously written off	32	44
Ending balance	81	62
Other receivables
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	1	1
Current period provision	0	0
Write-offs charged against allowance	0	0
Recoveries of amounts previously written off	0	0
Ending balance	$ 1	$ 1