Income Taxes (Details Textuals) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Entity Information [Line Items]
Deferred tax asset, general business tax credit carryforwards	$ 181,000,000
Deferred tax asset, alternative minimum tax credit carryforwards	284,000,000
State and local net operating loss carry-forwards	63,000,000	$ 39,000,000
Valuation allowance	35,000,000	31,000,000
Unrecognized tax benefits that would impact effective tax rate	2,000,000	2,000,000
Interest on income taxes accrued	1,000,000	1,000,000
Income tax penalties accrued	0
Federal
Entity Information [Line Items]
Operating loss carryforward	517,000,000
Windfall tax benefit	9,000,000
DTE Electric
Entity Information [Line Items]
Income tax receivable from related party	6,000,000	29,000,000
State and local net operating loss carry-forwards	16,000,000	0
Valuation allowance	0	0
Unrecognized tax benefits that would impact effective tax rate	3,000,000	2,000,000
Interest on income taxes accrued	$ 1,000,000	$ 1,000,000