Commitments and Contingencies (Details Textuals) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2012 deted kWh weeks employees years	Jun. 30, 2011	Dec. 31, 2011
Loss Contingencies [Line Items]
Environmental Capital Expenditures Through Current Year			$ 1,700,000,000
Environmental Capital Expenditures in Current Year	186,000,000
Environmental Capital Expenditures In Future Years	2,000,000,000
EPA is Alleging Detroit Edison Power Plants Violated New Source Performance Standards	5
Possible Additional Capital Expenditures for EPA Regulations	80,000,000		55,000,000
Minimum Amount of Years to Incur Additional Capital Expenditures	4
Maximum Amount of Years to Incur Additional Capital Expenditures	6
Former MGP Sites	3
Site Contingency, Accrual, Undiscounted Amount	8,000,000		8,000,000
Waiting Period of Policy	12
Insurance Coverage for Extra Expense when to Necessitate Power Plant when Unavailable	490,000,000
Period of coverage of policy for extra expenses	3
Primary Coverage	500,000,000
Coverage for Stabilization Decontamination Debris Removal Repair and Replacement of Property and Decommissioning	2,250,000,000
Combined coverage limit for total property damage	2,750,000,000
Insurance Deductible for Nuclear Power Plant	1,000,000
NEIL Policies Against Terrorism Loss		3,200,000,000
Amount Per Event Loss Associated With Nuclear Power Plants	31,000,000
Maintenance of Public Liability Insurance for Nuclear Power Plants	375,000,000
Aggregate Limit of Liabilities Arises From Terrorist Act Outside Scope of Trials Subject to One Industry	300,000,000
Deferred premium charges levied against each licensed nuclear facility	117,500,000
Limit deferred premium charges per year	17,500,000
Company Obligated to Pay DOE Fee of Fermi 2 Electricity Generated and Sold	1
Payment from the DOE for Delaying Acceptance of Spent Nuclear Fuel	48,000,000
Number of Represented Employees	2,800
Contract Expiring for Electrical Linemen	500
Long-term Purchase Commitment, Amount	1,400,000,000
Estimated Future Capital Expenditures for Current Year	$ 1,300,000,000