Property, Plant, and Equipment (Depreciation and Amortization) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	$ 740	$ 683	$ 630
Regulatory assets and liabilities	150	159	163
Securitized regulatory assets	38	(303)	(301)
Depreciation and amortization	852	1,145	1,094
Depreciation and amortization	852	1,145	1,094
DTE Electric
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	545	489	457
Regulatory assets and liabilities	126	135	138
Securitized regulatory assets	38	(303)	(301)
Depreciation and amortization	633	927	896
Depreciation and amortization	$ 633	$ 927	$ 896