Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 565	$ 663
Derivative Liabilities	(572)	(669)
Current derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	449	563
Current derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(434)	(518)
Noncurrent derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	116	100
Noncurrent derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(138)	(151)
Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(15)	(3)
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	235	349
Derivative Liabilities	(236)	(380)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	320	303
Derivative Liabilities	(321)	(285)
Other
Derivatives, Fair Value [Line Items]
Derivative Assets	9	7
Derivative Liabilities	0	(1)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	1	4
Derivatives designated as hedging instruments | Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(15)	(3)
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	565	663
Derivative Liabilities	(557)	(666)
Derivatives not designated as hedging instruments | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	9	6
Derivatives not designated as hedging instruments | Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	235	349
Derivative Liabilities	(236)	(380)
Derivatives not designated as hedging instruments | Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	320	303
Derivative Liabilities	(321)	(285)
Derivatives not designated as hedging instruments | Other
Derivatives, Fair Value [Line Items]
Derivative Assets	9	7
Derivative Liabilities	0	(1)
Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	1	4
Derivative Liabilities	0	0
Derivatives not designated as hedging instruments | FTRs — Other current assets | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 9	$ 6