Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 560	$ 567
Derivative Liabilities	(652)	(533)
Current derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	371	446
Current derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(369)	(386)
Noncurrent derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	189	121
Noncurrent derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(283)	(147)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(6)	(5)
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	163	233
Derivative Liabilities	(246)	(223)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	138	180
Derivative Liabilities	(150)	(168)
Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	259	154
Derivative Liabilities	(250)	(137)
Derivatives designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(4)	(4)
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	560	567
Derivative Liabilities	(648)	(529)
Derivatives not designated as hedging instruments | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	1	4
Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(2)	(1)
Derivatives not designated as hedging instruments | Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	163	233
Derivative Liabilities	(246)	(223)
Derivatives not designated as hedging instruments | Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	138	180
Derivative Liabilities	(150)	(168)
Derivatives not designated as hedging instruments | Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	259	154
Derivative Liabilities	(250)	(137)
Derivatives not designated as hedging instruments | FTRs — Other current assets | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 1	$ 4