Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 401	$ 361
Less: Allocation of earnings to net restricted stock awards	1	1
Net income available to common shareholders — basic	$ 400	$ 360
Average number of common shares outstanding — basic (in shares)	182.0	180.0
Basic Earnings per Common Share (in dollars per share)	$ 2.20	$ 2.01
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	$ 401	$ 361
Less: Allocation of earnings to net restricted stock awards	1	1
Net income available to common shareholders — diluted	$ 400	$ 360
Average number of common shares outstanding — basic (in shares)	182.0	180.0
Incremental shares attributable to:
Average dilutive equity units, performance share awards, and stock options (in shares)	1.0	0.0
Average number of common shares outstanding — diluted (in shares)	183.0	180.0
Diluted Earnings per Common Share (in dollars per share)	$ 2.19	$ 2.00
Antidilutive securities excluded from computation of earnings per share (in shares)		6.6