Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Derivative Assets
Derivative asset, gross	$ 607	$ 1,178
Derivative asset, netting	(482)	(1,006)
Derivative assets, net	125	172
Derivative Liabilities
Derivative liability, gross	(601)	(1,110)
Derivative liability, netting	517	1,025
Derivative liabilities, net	(84)	(85)
Current derivative liability
Derivative Liabilities
Derivative liability, gross	(501)	(1,041)
Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(100)	(69)
Natural Gas
Derivative Assets
Derivative asset, gross	251	787
Derivative asset, netting	(198)	(681)
Derivative assets, net	53	106
Derivative Liabilities
Derivative liability, gross	(256)	(718)
Derivative liability, netting	215	679
Derivative liabilities, net	(41)	(39)
Electricity
Derivative Assets
Derivative asset, gross	312	342
Derivative asset, netting	(249)	(280)
Derivative assets, net	63	62
Derivative Liabilities
Derivative liability, gross	(305)	(342)
Derivative liability, netting	265	298
Derivative liabilities, net	(40)	(44)
Other
Derivative Assets
Derivative asset, gross	37	45
Derivative asset, netting	(31)	(42)
Derivative assets, net	6	3
Derivative Liabilities
Derivative liability, gross	(34)	(45)
Derivative liability, netting	33	45
Derivative liabilities, net	(1)	0
Other derivative contract
Derivative Assets
Derivative asset, gross	7	4
Derivative asset, netting	(4)	(3)
Derivative assets, net	3	1
Derivative Liabilities
Derivative liability, gross	(6)	(5)
Derivative liability, netting	4	3
Derivative liabilities, net	(2)	(2)
Recurring
ASSETS
Cash and cash equivalents	12	112
Nuclear decommissioning trusts	1,267	1,241
Other investments	149	150
Derivative Assets
Derivative asset, netting	(482)	(1,006)
Derivative assets, net	125	172
Total assets	1,553	1,675
Derivative Liabilities
Derivative liability, netting	517	1,025
Derivative liabilities, net	(84)	(85)
Net asset (liability)	1,469	1,590
Net assets (liabilities), netting	35	19
Recurring | Current asset
Derivative Assets
Derivative asset, netting	(417)	(955)
Total assets	101	240
Recurring | Noncurrent asset
Derivative Assets
Derivative asset, netting	(65)	(51)
Total assets	1,452	1,435
Recurring | Current derivative liability
Derivative Liabilities
Derivative liability, netting	439	964
Derivative liabilities, net	(62)	(77)
Recurring | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, netting	78	61
Derivative liabilities, net	(22)	(8)
Recurring | Natural Gas
Derivative Assets
Derivative asset, netting	(198)	(681)
Derivative assets, net	53	106
Derivative Liabilities
Derivative liability, netting	215	679
Derivative liabilities, net	(41)	(39)
Recurring | Electricity
Derivative Assets
Derivative asset, netting	(249)	(280)
Derivative assets, net	63	62
Derivative Liabilities
Derivative liability, netting	265	298
Derivative liabilities, net	(40)	(44)
Recurring | Other
Derivative Assets
Derivative asset, netting	(31)	(42)
Derivative assets, net	6	3
Derivative Liabilities
Derivative liability, netting	33	45
Derivative liabilities, net	(1)	0
Recurring | Other derivative contract
Derivative Assets
Derivative asset, netting	(4)	(3)
Derivative assets, net	3	1
Derivative Liabilities
Derivative liability, netting	4	3
Derivative liabilities, net	(2)	(2)
Recurring | Level 1
ASSETS
Cash and cash equivalents	10	13
Nuclear decommissioning trusts	808	792
Other investments	99	100
Derivative Assets
Derivative asset, gross	141	597
Total assets	1,058	1,502
Derivative Liabilities
Derivative liability, gross	(164)	(610)
Net asset (liability)	894	892
Recurring | Level 1 | Current asset
Derivative Assets
Total assets	127	582
Recurring | Level 1 | Noncurrent asset
Derivative Assets
Total assets	931	920
Recurring | Level 1 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	(129)	(572)
Recurring | Level 1 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(35)	(38)
Recurring | Level 1 | Natural Gas
Derivative Assets
Derivative asset, gross	109	555
Derivative Liabilities
Derivative liability, gross	(140)	(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	32	42
Derivative Liabilities
Derivative liability, gross	(24)	(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	2	99
Nuclear decommissioning trusts	459	449
Other investments	50	50
Derivative Assets
Derivative asset, gross	375	439
Total assets	886	1,037
Derivative Liabilities
Derivative liability, gross	(342)	(382)
Net asset (liability)	544	655
Recurring | Level 2 | Current asset
Derivative Assets
Total assets	319	504
Recurring | Level 2 | Noncurrent asset
Derivative Assets
Total assets	567	533
Recurring | Level 2 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	(292)	(357)
Recurring | Level 2 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(50)	(25)
Recurring | Level 2 | Natural Gas
Derivative Assets
Derivative asset, gross	100	140
Derivative Liabilities
Derivative liability, gross	(66)	(78)
Recurring | Level 2 | Electricity
Derivative Assets
Derivative asset, gross	268	295
Derivative Liabilities
Derivative liability, gross	(264)	(290)
Recurring | Level 2 | Other
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	(6)	(9)
Recurring | Level 2 | Other derivative contract
Derivative Assets
Derivative asset, gross	7	4
Derivative Liabilities
Derivative liability, gross	(6)	(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	91	142
Total assets	91	142
Derivative Liabilities
Derivative liability, gross	(95)	(118)
Net asset (liability)	(4)	24
Recurring | Level 3 | Current asset
Derivative Assets
Total assets	72	109
Recurring | Level 3 | Noncurrent asset
Derivative Assets
Total assets	19	33
Recurring | Level 3 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	(80)	(112)
Recurring | Level 3 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	(15)	(6)
Recurring | Level 3 | Natural Gas
Derivative Assets
Derivative asset, gross	42	92
Derivative Liabilities
Derivative liability, gross	(50)	(62)
Recurring | Level 3 | Electricity
Derivative Assets
Derivative asset, gross	44	47
Derivative Liabilities
Derivative liability, gross	(41)	(52)
Recurring | Level 3 | Other
Derivative Assets
Derivative asset, gross	5	3
Derivative Liabilities
Derivative liability, gross	(4)	(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	7	104
Nuclear decommissioning trusts	1,267	1,241
Other investments	8	147
Derivative Assets
Total assets	1,287	1,495
DTE Electric | Recurring | Current asset
Derivative Assets
Total assets	12	107
DTE Electric | Recurring | Noncurrent asset
Derivative Assets
Total assets	1,275	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	808	792
Other investments	8	97
Derivative Assets
Total assets	821	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	816	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	2	99
Nuclear decommissioning trusts	459	449
Other investments	0	50
Derivative Assets
Total assets	461	598
DTE Electric | Recurring | Level 2 | Current asset
Derivative Assets
Total assets	2	99
DTE Electric | Recurring | Level 2 | Noncurrent asset
Derivative Assets
Total assets	459	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