Short-Term Credit Arrangements and Borrowings (Details Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 banks	Dec. 31, 2011
Short-term Debt [Line Items]
Revolving Credit Facilities with a Syndicate Number of Banks	20
Number of Banks that Provide Percentage of Commitment in any Facility	1
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 Capitilization Ration Denominator	1
Letters of Credit Outstanding, Amount	$ 73
Short-term Debt, Weighted Average Interest Rate	0.40%	0.50%
Borrowing Capacity Under Financing Agreement With iss 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	$ 65	$ 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
DTE Electric [Member]
Short-term Debt [Line Items]
Total Funded Debt to Total Capitalization Ratio	0.52
Total Funded Debt to Total Capitalization Ratio Denominator	1
DTE Gas [Member]
Short-term Debt [Line Items]
Total Funded Debt to Total Capitalization Ratio	0.46
Total Funded Debt to Total Capitalization Ratio Denominator	1