Supplementary Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Entity Information [Line Items]
Operating Revenues	$ 2,487	$ 2,598	$ 2,268	$ 2,984	$ 3,078	$ 2,595	$ 2,698	$ 3,930	$ 10,337	$ 12,301	$ 9,661
Operating Income	134	440	204	461	542	239	249	560	1,239	1,590	1,203
Net Income	$ 80	$ 265	$ 109	$ 273	$ 299	$ 156	$ 124	$ 326	$ 727	$ 905	$ 661
Basic Earnings per Share (in dollars per share)	$ 0.45	$ 1.47	$ 0.61	$ 1.53	$ 1.68	$ 0.88	$ 0.70	$ 1.84	$ 4.05	$ 5.11	$ 3.76
Diluted Earnings per Share (in dollars per share)	$ 0.45	$ 1.47	$ 0.61	$ 1.53	$ 1.68	$ 0.88	$ 0.70	$ 1.84	$ 4.05	$ 5.10	$ 3.76
DTE Electric
Entity Information [Line Items]
Operating Revenues	$ 1,165	$ 1,385	$ 1,147	$ 1,203	$ 1,234	$ 1,357	$ 1,281	$ 1,410	$ 4,900	$ 5,282	$ 5,197
Operating Income	192	400	214	268	250	272	259	271	1,074	1,052	1,000
Net Income	$ 92	$ 216	$ 99	$ 137	$ 129	$ 136	$ 130	$ 137	$ 544	$ 532	$ 487