Segment and Related Information (Financial Data - Net Income or Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 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	$ 109	$ 124	$ 382	$ 450
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	99	129	235	265
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	(7)	(4)	104	125
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	25	18	52	39
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	8	13	41	28
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	(3)	(14)	(12)	28
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	$ (13)	$ (18)	$ (38)	$ (35)