New Accounting Pronouncements (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 169
Lease liabilities for certain operating leases	160
DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	87
Lease liabilities for certain operating leases	$ 79
Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 137
Lease liabilities for certain operating leases		130
Prepaid lease costs reclassified from Other assets, current and noncurrent		9
Prepaid lease costs reclassified from Other liabilities, current and noncurrent		2
Accounting Standards Update 2018-02 | DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		74
Lease liabilities for certain operating leases		67
Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		0
Accumulated Other Comprehensive Income (Loss) | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		(25)
Retained Earnings | Accounting Standards Update 2018-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		$ 25