Significant Accounting Policies (Roll-Forward of Activity for Financing Receivables Credit Loss Reserves) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 72	$ 63	$ 79
Current period provision	69	76	52
Write-offs charged against allowance	(116)	(108)	(112)
Recoveries of amounts previously written off	37	41	44
Ending balance	62	72	63
DTE Electric
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	46	41	49
Current period provision	44	49	36
Write-offs charged against allowance	(74)	(70)	(72)
Recoveries of amounts previously written off	25	26	28
Ending balance	41	46	41
Trade accounts receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	69	62	78
Current period provision	69	74	52
Write-offs charged against allowance	(116)	(108)	(112)
Recoveries of amounts previously written off	37	41	44
Ending balance	59	69	62
Other receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	1	1
Current period provision	0	2	0
Write-offs charged against allowance	0	0	0
Recoveries of amounts previously written off	0	0	0
Ending balance	$ 3	$ 3	$ 1