Fair Value (Reconciliation of Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of December 31	$ 19	$ 13
Transfers into Level 3 from Level 2	0	2
Transfers from Level 3 into Level 2	0	2
Total gains (losses)
Included in earnings	(154)	(59)
Recorded in Regulatory liabilities	(3)	(2)
Purchases, issuances, and settlements
Settlements	69	(45)
Net Assets (Liabilities) as of March 31	(69)	(89)
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	(51)	(110)
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	1	0
Natural gas
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of December 31	27	(18)
Transfers into Level 3 from Level 2	0	2
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	(72)	(22)
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements
Settlements	65	38
Net Assets (Liabilities) as of March 31	20	0
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	2	(17)
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	0	0
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of December 31	(19)	24
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	(85)	(37)
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements
Settlements	11	(78)
Net Assets (Liabilities) as of March 31	(93)	(91)
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	(53)	(92)
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	0	0
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of December 31	11	7
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	0	2
Total gains (losses)
Included in earnings	3	0
Recorded in Regulatory liabilities	(3)	(2)
Purchases, issuances, and settlements
Settlements	(7)	(5)
Net Assets (Liabilities) as of March 31	4	2
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	0	(1)
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	1	0
DTE Electric
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of December 31	11	9
Total gains (losses)
Recorded in Regulatory liabilities	(3)	(2)
Purchases, issuances, and settlements
Settlements	(4)	(4)
Net Assets (Liabilities) as of March 31	4	3
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at end of period	$ 1	$ 0