Related Party Transactions (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Costs and Expenses [Abstract]
Fuel and power purchases	$ 1,668	$ 1,758	$ 1,716
Other [Abstract]
Dividends declared	342	317	306
Dividends paid	342	317	305
Capital Contribution	400
Assets [Abstract]
Accounts receivable (includes income taxes receivable of $23 in 2013)	24	5
Notes Receivable - Affiliates	200	0
Liabilities [Abstract]
Accounts payable (includes income taxes payable of $13 in 2012)	60	65
Short-term borrowing - affiliates	58	80
Accrued pension liability — affiliates	705	1,368
Accrued postretirement liability — affiliates	369	996
DTE Energy [Member]
Revenues [Abstract]
Energy sales	2	2	1
Other services	7	11	4
Shared capital assets	23	26	30
Costs and Expenses [Abstract]
Fuel and power purchases	4	5	1
Other services and interest	(1)	1	2
Corporate expenses (net)	334	322	304
Other [Abstract]
Dividends declared	342	317	305
Dividends paid	342	317	305
Capital Contribution	400	0	0
Assets [Abstract]
Accounts receivable (includes income taxes receivable of $23 in 2013)	24	5
Income Taxes Receivable	23	0
Notes Receivable - Affiliates	200	0
Liabilities [Abstract]
Accounts payable (includes income taxes payable of $13 in 2012)	60	65
Income Taxes Payable	0	13
Short-term borrowing - affiliates	58	80
Accrued pension liability — affiliates	705	1,368
Accrued postretirement liability — affiliates	$ 369	$ 996