Organization and Basis of Presentation (Details) (USD $) In Millions	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Entity Information [Line Items]
Number of Detroit Edison Customers	approximately 2.1 million
Number of MichCon Customers	approximately 1.2 million
ASSETS
Cash and cash equivalents	$ 61	$ 65	$ 124	$ 52
Restricted cash	118	120
Accounts receivable	1,297	1,393
Other current assets	223	255
Property, plant and equipment	13,284	12,992
Securitized regulatory assets	656	729
Other assets	195	206
Total Assets	24,579	24,896
LIABILITIES
Current portion long-term debt, including capital leases	326	925
Other current liabilities	517	597
Mortgage bonds, notes and other	6,622	6,114
Securitization bonds	559	643
Capital lease obligations	37	43
Other long term liabilities	250	275
Summary of amounts for non-consolidated VIEs
Other investments	526	518
Trust preferred-linked securities	289	289
Detroit Edison [Member]
Entity Information [Line Items]
Number of Detroit Edison Customers	approximately 2.1 million
MichCon [Member]
Entity Information [Line Items]
Number of MichCon Customers	approximately 1.2 million
Consolidated Variable Interest Entities [Member]
ASSETS
Cash and cash equivalents	11	4
Restricted cash	111	112
Accounts receivable	50	50
Inventories	113	99
Other current assets	1	1
Property, plant and equipment	60	54
Securitized regulatory assets	656	729
Other assets	20	22
Total Assets	1,022	1,071
LIABILITIES
Accounts payable and accrued current liabilities	79	44
Current portion long-term debt, including capital leases	165	157
Other current liabilities	61	68
Mortgage bonds, notes and other	32	35
Securitization bonds	559	643
Capital lease obligations	21	23
Other long term liabilities	8	13
Total Liabilities	925	983
Consolidated Variable Interest Entities [Member] | Securitization [Member]
ASSETS
Cash and cash equivalents	0	0
Restricted cash	106	104
Accounts receivable	34	42
Inventories	0	0
Other current assets	0	0
Property, plant and equipment	0	0
Securitized regulatory assets	656	729
Other assets	12	13
Total Assets	808	888
LIABILITIES
Accounts payable and accrued current liabilities	16	17
Current portion long-term debt, including capital leases	158	150
Other current liabilities	59	62
Mortgage bonds, notes and other	0	0
Securitization bonds	559	643
Capital lease obligations	0	0
Other long term liabilities	6	6
Total Liabilities	798	878
Consolidated Variable Interest Entities [Member] | Others [Member]
ASSETS
Cash and cash equivalents	11	4
Restricted cash	5	8
Accounts receivable	16	8
Inventories	113	99
Other current assets	1	1
Property, plant and equipment	60	54
Securitized regulatory assets	0	0
Other assets	8	9
Total Assets	214	183
LIABILITIES
Accounts payable and accrued current liabilities	63	27
Current portion long-term debt, including capital leases	7	7
Other current liabilities	2	6
Mortgage bonds, notes and other	32	35
Securitization bonds	0	0
Capital lease obligations	21	23
Other long term liabilities	2	7
Total Liabilities	127	105
Consolidated Variable Interest Entities [Member] | Restricted Amounts [Member]
ASSETS
Cash and cash equivalents	0	0
Restricted cash	111	112
Accounts receivable	36	44
Inventories	0	0
Other current assets	0	0
Property, plant and equipment	26	38
Securitized regulatory assets	656	729
Other assets	20	21
Total Assets	849	944
LIABILITIES
Accounts payable and accrued current liabilities	16	18
Current portion long-term debt, including capital leases	165	157
Other current liabilities	61	66
Mortgage bonds, notes and other	32	35
Securitization bonds	559	643
Capital lease obligations	21	23
Other long term liabilities	8	12
Total Liabilities	862	954
Non-consolidated Variable Interest Entities [Member]
Summary of amounts for non-consolidated VIEs
Other investments	113	98
Note receivable	5	6
Trust preferred-linked securities	$ 289	$ 289