Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 663	$ 652
Derivative Liabilities	(669)	(657)
Current derivative asset
Derivatives, Fair Value [Line Items]
Derivative Assets	563	540
Noncurrent derivative asset
Derivatives, Fair Value [Line Items]
Derivative Assets	100	112
Current derivative liability
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(518)	(558)
Noncurrent derivative liability
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(151)	(99)
Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(3)	0
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	349	357
Derivative Liabilities	(380)	(378)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	303	285
Derivative Liabilities	(285)	(275)
Other
Derivatives, Fair Value [Line Items]
Derivative Assets	7	9
Derivative Liabilities	(1)	(1)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	4	1
Derivative Liabilities	0	(3)
Derivatives designated as hedging instruments | Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(3)	0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	663	652
Derivative Liabilities	(666)	(657)
Derivatives not designated as hedging instruments | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	6	9
Derivatives not designated as hedging instruments | Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	349	357
Derivative Liabilities	(380)	(378)
Derivatives not designated as hedging instruments | Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	303	285
Derivative Liabilities	(285)	(275)
Derivatives not designated as hedging instruments | Other
Derivatives, Fair Value [Line Items]
Derivative Assets	7	9
Derivative Liabilities	(1)	(1)
Derivatives not designated as hedging instruments | FTRs — Other current assets | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	6	9
Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	4	1
Derivative Liabilities	$ 0	$ (3)