Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 319	$ 334	$ 902	$ 929
Less: Allocation of earnings to net restricted stock awards	1	1	2	2
Net income available to common shareholders — basic	$ 318	$ 333	$ 900	$ 927
Average number of common shares outstanding — basic (in shares)	183.0	182.0	183.0	181.0
Basic Earnings per Common Share (in dollars per share)	$ 1.74	$ 1.84	$ 4.93	$ 5.13
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	$ 319	$ 334	$ 902	$ 929
Less: Allocation of earnings to net restricted stock awards	1	1	2	2
Net income available to common shareholders — diluted	$ 318	$ 333	$ 900	$ 927
Average number of common shares outstanding — basic (in shares)	183.0	182.0	183.0	181.0
Incremental shares attributable to:
Average dilutive equity units, performance share awards, and stock options (in shares)	1.0	0.0	1.0	0.0
Average number of common shares outstanding — diluted (in shares)	184.0	182.0	184.0	181.0
Diluted Earnings per Common Share (in dollars per share)	$ 1.73	$ 1.84	$ 4.91	$ 5.13
Antidilutive securities excluded from computation of earnings per share (in shares)		6.2		6.4