Retirement Benefits and Trusteed Assets (Details Textuals) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company Contribution to Employee Savings Plan		4.00%
Company Retiree New Coverage Minimum		$ 3,250
Company Retiree New Coverage Maximum		3,500
Retiree Health Care Allowance will increase at lower of the rate of medical inflation or a set percentage		2.00%
Retiree Health Care Allowance	3,250
Prescription Drug Benefit, Effect of Subsidy on Net Periodic Postretirement Benefit Cost		1,000,000	6,000,000	6,000,000
Grantor Trust Balance		17,000,000	14,000,000
Defined Contribution Plan, Cost Recognized		41,000,000	37,000,000	35,000,000
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions		284,000,000	240,000,000
Estimated Future Employer Contributions in Next Fiscal Year		345,000,000
Defined Benefit Plan, Expected Return on Plan Assets		7.75%
Transfers between Level 3 and Level 2		0	0
Transfers between Level 2 and Level 1		0	0
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		4.95%	4.15%	5.00%
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions		264,000,000	140,000,000
Estimated Future Employer Contributions in Next Fiscal Year		145,000,000
Defined Benefit Plan, Expected Return on Plan Assets		8.00%
Transfers between Level 3 and Level 2		0	0
Transfers between Level 2 and Level 1		0	0
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components		9,000,000
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation		124,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components		8,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation		108,000,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.30%	4.95%	4.15%	5.00%
Retiree Healthcare Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Cost Recognized		2,000,000	0
DTE Gas Represented Employees [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company Contribution to Employee Savings Plan		8.00%
Qualified Plans [Member] | Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions		$ 277,000,000