Short-Term Credit Arrangements and Borrowings (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Mar. 31, 2013 banks	Jun. 30, 2013 banks	Dec. 31, 2012
Short-term Debt [Line Items]
Revolving Credit Facilities with a Syndicate Number of Banks	20	19
Number of Banks that Provide Percentage of Commitment in any Facility	1
Time Period of Amended and Restated Credit Agreement		5 years
Maximum Percentage of Commitment to Bank in any Facility	8.50%	8.70%
Line of Credit Facility, Current Borrowing Capacity	$ 1,975
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	39
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	58		65
DTE Energy [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	1,275
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]
Line of Credit Facility, Current Borrowing Capacity	300
Total Funded Debt to Total Capitalization Ratio	0.53
Total Funded Debt to Total Capitalization Ratio Denominator	1
DTE Gas [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	400
Total Funded Debt to Total Capitalization Ratio	0.45
Total Funded Debt to Total Capitalization Ratio Denominator	1
Unsecured Revolving Facility 4 [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	1,800
Unsecured Revolving Facility 4 [Member] | DTE Energy [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	1,100	1,200
Unsecured Revolving Facility 4 [Member] | DTE Electric [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	300
Unsecured Revolving Facility 4 [Member] | DTE Gas [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 400	$ 300