Segment and Related Information (Profit (Loss) Financial Data) (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2026	Jun. 30, 2026	Mar. 31, 2026	Sep. 30, 2025	Jun. 30, 2025	Mar. 31, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025
Segment Reporting [Line Items]
Operating Revenues — Utility operations	$ 2,270			$ 2,223			$ 6,937	$ 6,509
Operating Revenues — Non-utility operations	1,457			1,304			5,300	4,877
Depreciation and amortization	506			464			1,487	1,367
Interest expense	317			271			911	777
Interest income	(32)			(26)			(96)	(74)
Equity earnings of equity method investees	5			5			12	16
Other segment items (pre-tax)	2,568			2,400			9,130	8,230
Income Tax Expense (Benefit)	(107)			(6)			(206)	(23)
Net Income (Loss) Attributable to DTE Energy Company	470	$ 282	$ 247	419	$ 229	$ 445	999	1,093
Other Financial Data
Investments in equity method investees	112						112		$ 122
Capital expenditures and acquisitions							4,112		4,639
Goodwill	1,993						1,993		1,993
Total Assets	57,594						57,594		54,066
Operating segments
Segment Reporting [Line Items]
Operating Revenues — Utility operations	2,295			2,246			7,010	6,574
Operating Revenues — Non-utility operations	1,515			1,356			5,497	5,072
Depreciation and amortization	506			464			1,487	1,367
Interest expense	212			185			611	540
Interest income	(31)			(27)			(97)	(83)
Equity earnings of equity method investees	5			5			12	17
Other segment items (pre-tax)	2,650			2,473			9,394	8,481
Income Tax Expense (Benefit)	(103)			(32)			(122)	16
Net Income (Loss) Attributable to DTE Energy Company	571			534			1,222	1,308
Other Financial Data
Investments in equity method investees	101						101		100
Capital expenditures and acquisitions							4,112		4,639
Goodwill	1,993						1,993		1,993
Total Assets	55,684						55,684		52,096
Operating segments | Electric segment
Segment Reporting [Line Items]
Operating Revenues — Utility operations	2,081			2,037			5,549	5,173
Operating Revenues — Non-utility operations	22			14			73	23
Depreciation and amortization	431			390			1,263	1,152
Interest expense	164			143			470	414
Interest income	(3)			(2)			(10)	(6)
Equity earnings of equity method investees	0			0			0	0
Other segment items (pre-tax)	1,073			1,028			2,999	2,716
Income Tax Expense (Benefit)	(30)			(14)			(56)	(27)
Net Income (Loss) Attributable to DTE Energy Company	468			506			956	947
Other Financial Data
Investments in equity method investees	4						4		4
Capital expenditures and acquisitions							3,486		3,892
Goodwill	1,208						1,208		1,208
Total Assets	42,583						42,583		39,370
Operating segments | Gas segment
Segment Reporting [Line Items]
Operating Revenues — Utility operations	214			209			1,461	1,401
Operating Revenues — Non-utility operations	0			0			0	0
Depreciation and amortization	59			59			176	168
Interest expense	35			33			105	97
Interest income	(2)			(3)			(6)	(9)
Equity earnings of equity method investees	0			0			1	1
Other segment items (pre-tax)	161			171			956	918
Income Tax Expense (Benefit)	(9)			(13)			53	52
Net Income (Loss) Attributable to DTE Energy Company	(30)			(38)			176	174
Other Financial Data
Investments in equity method investees	20						20		19
Capital expenditures and acquisitions							583		661
Goodwill	743						743		743
Total Assets	9,267						9,267		8,987
Operating segments | DTE Vantage segment
Segment Reporting [Line Items]
Operating Revenues — Utility operations	0			0			0	0
Operating Revenues — Non-utility operations	201			163			628	520
Depreciation and amortization	15			15			45	44
Interest expense	9			6			23	22
Interest income	(25)			(21)			(76)	(62)
Equity earnings of equity method investees	5			5			11	16
Other segment items (pre-tax)	159			141			646	434
Income Tax Expense (Benefit)	(72)			(16)			(117)	(37)
Net Income (Loss) Attributable to DTE Energy Company	110			33			96	103
Other Financial Data
Investments in equity method investees	77						77		77
Capital expenditures and acquisitions							40		80
Goodwill	25						25		25
Total Assets	2,729						2,729		2,426
Operating segments | Energy Trading segment
Segment Reporting [Line Items]
Operating Revenues — Utility operations	0			0			0	0
Operating Revenues — Non-utility operations	1,292			1,179			4,796	4,529
Depreciation and amortization	1			0			3	3
Interest expense	4			3			13	7
Interest income	(1)			(1)			(5)	(6)
Equity earnings of equity method investees	0			0			0	0
Other segment items (pre-tax)	1,257			1,133			4,793	4,413
Income Tax Expense (Benefit)	8			11			(2)	28
Net Income (Loss) Attributable to DTE Energy Company	23			33			(6)	84
Other Financial Data
Investments in equity method investees	0						0		0
Capital expenditures and acquisitions							3		6
Goodwill	17						17		17
Total Assets	1,105						1,105		1,313
Corporate and Other
Segment Reporting [Line Items]
Operating Revenues — Utility operations	0			0			0	0
Operating Revenues — Non-utility operations	0			0			0	0
Depreciation and amortization	0			0			0	0
Interest expense	128			104			362	297
Interest income	(24)			(17)			(61)	(51)
Equity earnings of equity method investees	0			0			0	(1)
Other segment items (pre-tax)	1			2			6	9
Income Tax Expense (Benefit)	(4)			26			(84)	(39)
Net Income (Loss) Attributable to DTE Energy Company	(101)			(115)			(223)	(215)
Other Financial Data
Investments in equity method investees	11						11		22
Capital expenditures and acquisitions							0		0
Goodwill	0						0		0
Total Assets	6,167						6,167		5,145
Reclassifications and Eliminations
Segment Reporting [Line Items]
Operating Revenues — Utility operations	(25)			(23)			(73)	(65)
Operating Revenues — Non-utility operations	(58)			(52)			(197)	(195)
Depreciation and amortization	0			0			0	0
Interest expense	(23)			(18)			(62)	(60)
Interest income	23			18			62	60
Equity earnings of equity method investees	0			0			0	0
Other segment items (pre-tax)	(83)			(75)			(270)	(260)
Income Tax Expense (Benefit)	0			0			0	0
Net Income (Loss) Attributable to DTE Energy Company	0			0			0	0
Other Financial Data
Investments in equity method investees	0						0		0
Capital expenditures and acquisitions							0		0
Goodwill	0						0		0
Total Assets	(4,257)						(4,257)		$ (3,175)
Reclassifications and Eliminations | Electric segment
Segment Reporting [Line Items]
Operating Revenues — Non-utility operations	$ (1)			$ (1)			$ (3)	$ (3)