Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current income tax expense (benefit)
Federal	$ (3)	$ (16)	$ 74
State and other income tax	(4)	24	16
Total current income taxes	(7)	8	90
Deferred income tax expense
Federal	178	289	122
State and other income tax	59	67	42
Total deferred income taxes	237	356	164
Total	230	364	254
DTE Electric
Current income tax expense (benefit)
Federal	(26)	(19)	123
State and other income tax	(2)	20	23
Total current income taxes	(28)	1	146
Deferred income tax expense
Federal	252	251	68
State and other income tax	68	46	40
Total deferred income taxes	320	297	108
Total	$ 292	$ 298	$ 254