Retirement Benefits and Trusteed Assets (Pension Plan - Contributions to DTE Energy Company Affiliates Employee Benefit Plans Master Trust) (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Sep. 08, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Amount		$ 82	$ 100	$ 175
Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Number of Shares (in shares)	694,444
Price per Share (in dollars per share)	$ 118.08
Amount	$ 82