Supplementary Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Entity Information [Line Items]
Operating Revenues	$ 3,271	$ 3,245	$ 2,855	$ 3,236	$ 2,874	$ 2,928	$ 2,262	$ 2,566	$ 12,607	$ 10,630	$ 10,337
Operating Income	356	418	303	569	301	507	256	381	1,646	1,445	1,239
Net Income	$ 287	$ 270	$ 177	$ 400	$ 131	$ 338	$ 152	$ 247	$ 1,134	$ 868	$ 727
Basic Earnings per Share (in dollars per share)	$ 1.60	$ 1.51	$ 0.99	$ 2.23	$ 0.73	$ 1.88	$ 0.84	$ 1.38	$ 6.32	$ 4.84	$ 4.05
Diluted Earnings per Share (in dollars per share)	$ 1.60	$ 1.51	$ 0.99	$ 2.23	$ 0.73	$ 1.88	$ 0.84	$ 1.37	$ 6.32	$ 4.83	$ 4.05
Effect of the Tax Cuts and Jobs Act of 2017	$ (105)								$ (105)	$ 0	$ 0
DTE Electric
Entity Information [Line Items]
Operating Revenues	1,275	$ 1,434	$ 1,218	$ 1,175	$ 1,249	$ 1,608	$ 1,215	$ 1,153	5,102	5,225
Operating Income	281	395	272	217	193	501	265	245	1,165	1,204	1,074
Net Income	$ 138	$ 219	$ 138	$ 106	$ 75	$ 285	$ 135	$ 127	$ 601	$ 622	$ 544