Segment Information (Financial Data - Net Income or Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	$ 273	$ 326
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	136	136
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	111	129
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	21
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	33	15
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	(9)	42
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	$ (25)	$ (17)