Short-Term Credit Arrangements and Borrowings (Details Textuals) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Revolving Credit Facilities with a Syndicate Number of Banks	19
Number of Banks that Provide Percentage of Commitment in any Facility	1
Maximum Percentage of Commitment to Bank in any Facility	8.70%
Maximum Total Funded Debt to Total Capitalization Ratio	0.65
Maximum Total Funded Debt to Total Capitilization Ratio Denominator	1
Total Funded Debt to Total Capitalization Ratio	0.53
Total Funded Debt to Total Capitalization Ratio Denominator	1
DTE Electric [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Amount Outstanding	$ 96	$ 130