Segment and Related Information (Financial Data - Net Income or Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	$ 265	$ 156	$ 647	$ 606
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	214	135	449	400
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	(11)	(16)	93	109
Gas Storage and Pipelines
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	27	20	79	59
Power and Industrial Projects
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	32	38	73	66
Energy Trading
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	12	(22)	0	6
Corporate and Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	$ (9)	$ 1	$ (47)	$ (34)