Common Stock and Earnings Per Share (Basic and Diluted Income Per Share Calculation) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic Earnings per Share
Net Income attributable to DTE Energy — continuing operations	$ 58	$ 372	$ 495	$ 844
Less: Allocation of earnings to net restricted stock awards	0	1	1	2
Net income from continuing operations available to common shareholders — basic	58	371	494	842
Net Income (Loss) attributable to DTE Energy — discontinued operations	(33)	104	106	249
Net income available to common shareholders — basic	$ 25	$ 475	$ 600	$ 1,091
Average number of common shares outstanding — basic (in shares)	193.0	193.0	193.0	192.0
Continuing operations (in dollars per share)	$ 0.30	$ 1.93	$ 2.55	$ 4.37
Discontinued operations (in dollars per share)	(0.17)	0.54	0.55	1.30
Basic Earnings per Common Share (in dollars per share)	$ 0.13	$ 2.47	$ 3.10	$ 5.67
Diluted Earnings per Share
Net Income attributable to DTE Energy — continuing operations	$ 58	$ 372	$ 495	$ 844
Less: Allocation of earnings to net restricted stock awards	0	1	1	2
Net income from continuing operations available to common shareholders — diluted	58	371	494	842
Net Income (Loss) attributable to DTE Energy — discontinued operations	(33)	104	106	249
Net income available to common shareholders — diluted	$ 25	$ 475	$ 600	$ 1,091
Average number of common shares outstanding — basic (in shares)	193.0	193.0	193.0	192.0
Average dilutive equity units, performance share awards, and stock options (in shares)	1.0	0.0	1.0	1.0
Average number of common shares outstanding — diluted (in shares)	194.0	193.0	194.0	193.0
Continuing operations (in dollars per share)	$ 0.30	$ 1.92	$ 2.55	$ 4.37
Discontinued operations (in dollars per share)	(0.17)	0.54	0.55	1.29
Diluted Earnings per Common Share (in dollars per share)	$ 0.13	$ 2.46	$ 3.10	$ 5.66
Antidilutive securities excluded from computation of earnings per share (in shares)	11.1	10.3	11.5	10.3