Income Taxes (Deferred Tax Assets (Liabilities)) (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant, and equipment	$ (4,596)	$ (4,211)
Securitized regulatory assets	0	5
Tax credit carry-forwards	643	465
Pension and benefits	(324)	(301)
Federal net operating loss carry-forward	190	177
State and local net operating loss carry-forwards	59	63
Investments in equity method investees	(109)	(82)
Other	11	(4)
Deferred tax liabilities, gross	(4,126)	(3,888)
Less valuation allowance	(36)	(35)
Deferred income tax assets	1,463	1,088
Deferred income tax liabilities	(5,625)	(5,011)
Deferred income tax liabilities	(4,162)	(3,923)
DTE Electric
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant, and equipment	(3,702)	(3,468)
Securitized regulatory assets	0	5
Tax credit carry-forwards	116	53
Pension and benefits	(222)	(193)
Federal net operating loss carry-forward	42	142
State and local net operating loss carry-forwards	1	16
Investments in equity method investees	0	0
Other	(28)	(53)
Deferred tax liabilities, gross	(3,793)	(3,498)
Less valuation allowance	0	0
Deferred income tax assets	569	453
Deferred income tax liabilities	(4,362)	(3,951)
Deferred income tax liabilities	$ (3,793)	$ (3,498)