Short-Term Credit Arrangements and Borrowings (Details Textuals) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012 ratio banks percent	Dec. 31, 2011
Short-term Debt [Line Items]
Revolving Credit Facilities with a Syndicate Number of Banks	20
Maximum Percentage of Commitment to Bank in Any Facility	8.50%
Maximum Total Funded Debt to Total Capitalization Ratio	0.65
Maximum Total Funded Debt to Total Capitalization Ratio Denominator	1
Letters of Credit Outstanding, Amount	$ 91
Borrowing Capacity Under Financing Agreement with its Clearing Agent	100
Maximum Additional Margin Financing	50
Line of Credit Facility, Increase, Additional Borrowings	40
Line of Credit Facility Current Borrowing	140
Other Short-term Borrowings	$ 71	$ 56
DTE Energy [Member]
Short-term Debt [Line Items]
Total Funded Debt to Total Capitalization Ratio	0.48
Total Funded Debt to Total Capitalization Ratio Denominator	1
Detroit Edison [Member]
Short-term Debt [Line Items]
Total Funded Debt to Total Capitalization Ratio	0.52
Total Funded Debt to Total Capitalization Ratio Denominator	1
MichCon [Member]
Short-term Debt [Line Items]
Total Funded Debt to Total Capitalization Ratio	0.45
Total Funded Debt to Total Capitalization Ratio Denominator	1