Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Derivative Assets
Derivative asset, gross	$ 586	$ 1,178
Derivative asset, netting	(448)	(1,006)
Derivative assets, net	138	172
Derivative Liabilities
Derivative liability, gross	(551)	(1,110)
Derivative liability, netting	468	1,025
Derivative liabilities, net	(83)	(85)
Current derivative liability
Derivative Liabilities
Derivative liability, gross	(419)	(1,041)
Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(132)	(69)
Natural Gas
Derivative Assets
Derivative asset, gross	303	787
Derivative asset, netting	(244)	(681)
Derivative assets, net	59	106
Derivative Liabilities
Derivative liability, gross	(277)	(718)
Derivative liability, netting	249	679
Derivative liabilities, net	(28)	(39)
Electricity
Derivative Assets
Derivative asset, gross	251	342
Derivative asset, netting	(179)	(280)
Derivative assets, net	72	62
Derivative Liabilities
Derivative liability, gross	(244)	(342)
Derivative liability, netting	190	298
Derivative liabilities, net	(54)	(44)
Other
Derivative Assets
Derivative asset, gross	22	45
Derivative asset, netting	(17)	(42)
Derivative assets, net	5	3
Derivative Liabilities
Derivative liability, gross	(23)	(45)
Derivative liability, netting	22	45
Derivative liabilities, net	(1)	0
Other derivative contract
Derivative Assets
Derivative asset, gross	10	4
Derivative asset, netting	(8)	(3)
Derivative assets, net	2	1
Derivative Liabilities
Derivative liability, gross	(7)	(5)
Derivative liability, netting	7	3
Derivative liabilities, net	0	(2)
Recurring
ASSETS
Cash and cash equivalents	14	112
Nuclear decommissioning trusts	1,199	1,241
Other investments	145	150
Derivative Assets
Derivative asset, netting	(448)	(1,006)
Derivative assets, net	138	172
Total assets	1,496	1,675
Derivative Liabilities
Derivative liability, netting	468	1,025
Derivative liabilities, net	(83)	(85)
Net asset (liability)	1,413	1,590
Net assets (liabilities), netting	20	19
Recurring | Current asset
Derivative Assets
Derivative asset, netting	(358)	(955)
Total assets	104	240
Recurring | Noncurrent asset
Derivative Assets
Derivative asset, netting	(90)	(51)
Total assets	1,392	1,435
Recurring | Current derivative liability
Derivative Liabilities
Derivative liability, netting	363	964
Derivative liabilities, net	(56)	(77)
Recurring | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, netting	105	61
Derivative liabilities, net	(27)	(8)
Recurring | Natural Gas
Derivative Assets
Derivative asset, netting	(244)	(681)
Derivative assets, net	59	106
Derivative Liabilities
Derivative liability, netting	249	679
Derivative liabilities, net	(28)	(39)
Recurring | Electricity
Derivative Assets
Derivative asset, netting	(179)	(280)
Derivative assets, net	72	62
Derivative Liabilities
Derivative liability, netting	190	298
Derivative liabilities, net	(54)	(44)
Recurring | Other
Derivative Assets
Derivative asset, netting	(17)	(42)
Derivative assets, net	5	3
Derivative Liabilities
Derivative liability, netting	22	45
Derivative liabilities, net	(1)	0
Recurring | Other derivative contract
Derivative Assets
Derivative asset, netting	(8)	(3)
Derivative assets, net	2	1
Derivative Liabilities
Derivative liability, netting	7	3
Derivative liabilities, net	0	(2)
Recurring | Level 1
ASSETS
Cash and cash equivalents	11	13
Nuclear decommissioning trusts	742	792
Other investments	127	100
Derivative Assets
Derivative asset, gross	179	597
Total assets	1,059	1,502
Derivative Liabilities
Derivative liability, gross	(208)	(610)
Net asset (liability)	851	892
Recurring | Level 1 | Current asset
Derivative Assets
Total assets	159	582
Recurring | Level 1 | Noncurrent asset
Derivative Assets
Total assets	900	920
Recurring | Level 1 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	(160)	(572)
Recurring | Level 1 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(48)	(38)
Recurring | Level 1 | Natural Gas
Derivative Assets
Derivative asset, gross	162	555
Derivative Liabilities
Derivative liability, gross	(195)	(578)
Recurring | Level 1 | Electricity
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	0	0
Recurring | Level 1 | Other
Derivative Assets
Derivative asset, gross	17	42
Derivative Liabilities
Derivative liability, gross	(13)	(32)
Recurring | Level 1 | Other derivative contract
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	0	0
Recurring | Level 2
ASSETS
Cash and cash equivalents	3	99
Nuclear decommissioning trusts	457	449
Other investments	18	50
Derivative Assets
Derivative asset, gross	301	439
Total assets	779	1,037
Derivative Liabilities
Derivative liability, gross	(260)	(382)
Net asset (liability)	519	655
Recurring | Level 2 | Current asset
Derivative Assets
Total assets	225	504
Recurring | Level 2 | Noncurrent asset
Derivative Assets
Total assets	554	533
Recurring | Level 2 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	(198)	(357)
Recurring | Level 2 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(62)	(25)
Recurring | Level 2 | Natural Gas
Derivative Assets
Derivative asset, gross	87	140
Derivative Liabilities
Derivative liability, gross	(49)	(78)
Recurring | Level 2 | Electricity
Derivative Assets
Derivative asset, gross	204	295
Derivative Liabilities
Derivative liability, gross	(200)	(290)
Recurring | Level 2 | Other
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	(4)	(9)
Recurring | Level 2 | Other derivative contract
Derivative Assets
Derivative asset, gross	10	4
Derivative Liabilities
Derivative liability, gross	(7)	(5)
Recurring | Level 3
ASSETS
Cash and cash equivalents	0	0
Nuclear decommissioning trusts	0	0
Other investments	0	0
Derivative Assets
Derivative asset, gross	106	142
Total assets	106	142
Derivative Liabilities
Derivative liability, gross	(83)	(118)
Net asset (liability)	23	24
Recurring | Level 3 | Current asset
Derivative Assets
Total assets	78	109
Recurring | Level 3 | Noncurrent asset
Derivative Assets
Total assets	28	33
Recurring | Level 3 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	(61)	(112)
Recurring | Level 3 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(22)	(6)
Recurring | Level 3 | Natural Gas
Derivative Assets
Derivative asset, gross	54	92
Derivative Liabilities
Derivative liability, gross	(33)	(62)
Recurring | Level 3 | Electricity
Derivative Assets
Derivative asset, gross	47	47
Derivative Liabilities
Derivative liability, gross	(44)	(52)
Recurring | Level 3 | Other
Derivative Assets
Derivative asset, gross	5	3
Derivative Liabilities
Derivative liability, gross	(6)	(4)
Recurring | Level 3 | Other derivative contract
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	0	0
DTE Electric | Recurring
ASSETS
Cash and cash equivalents	8	104
Nuclear decommissioning trusts	1,199	1,241
Other investments	7	147
Derivative Assets
Total assets	1,219	1,495
DTE Electric | Recurring | Current asset
Derivative Assets
Total assets	13	107
DTE Electric | Recurring | Noncurrent asset
Derivative Assets
Total assets	1,206	1,388
DTE Electric | Recurring | Financial transmission rights
Derivative Assets
Derivative assets, net	5	3
DTE Electric | Recurring | Level 1
ASSETS
Cash and cash equivalents	5	5
Nuclear decommissioning trusts	742	792
Other investments	7	97
Derivative Assets
Total assets	754	894
DTE Electric | Recurring | Level 1 | Current asset
Derivative Assets
Total assets	5	5
DTE Electric | Recurring | Level 1 | Noncurrent asset
Derivative Assets
Total assets	749	889
DTE Electric | Recurring | Level 1 | Financial transmission rights
Derivative Assets
Derivative assets, net	0	0
DTE Electric | Recurring | Level 2
ASSETS
Cash and cash equivalents	3	99
Nuclear decommissioning trusts	457	449
Other investments	0	50
Derivative Assets
Total assets	460	598
DTE Electric | Recurring | Level 2 | Current asset
Derivative Assets
Total assets	3	99
DTE Electric | Recurring | Level 2 | Noncurrent asset
Derivative Assets
Total assets	457	499
DTE Electric | Recurring | Level 2 | Financial transmission rights
Derivative Assets
Derivative assets, net	0	0
DTE Electric | Recurring | Level 3
ASSETS
Cash and cash equivalents	0	0
Nuclear decommissioning trusts	0	0
Other investments	0	0
Derivative Assets
Total assets	5	3
DTE Electric | Recurring | Level 3 | Current asset
Derivative Assets
Total assets	5	3
DTE Electric | Recurring | Level 3 | Noncurrent asset
Derivative Assets
Total assets	0	0
DTE Electric | Recurring | Level 3 | Financial transmission rights
Derivative Assets
Derivative assets, net	$ 5	$ 3