Significant Accounting Policies (Roll-Forward of Activity for Financing Receivables Credit Loss Reserves) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 72	$ 63
Current period provision	25	76
Write-offs charged against allowance	(29)	(108)
Recoveries of amounts previously written off	9	41
Ending balance	77	72
DTE Electric
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	46	41
Current period provision	10	49
Write-offs charged against allowance	(19)	(70)
Recoveries of amounts previously written off	6	26
Ending balance	43	46
Trade accounts receivable
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	69	62
Current period provision	25	74
Write-offs charged against allowance	(29)	(108)
Recoveries of amounts previously written off	9	41
Ending balance	74	69
Other receivables
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	1
Current period provision	0	2
Write-offs charged against allowance	0	0
Recoveries of amounts previously written off	0	0
Ending balance	$ 3	$ 3