New Accounting Pronouncements (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases	$ 145
Lease liabilities for certain operating leases	138
Reclassification of income tax effects		$ 0	$ 0
DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases	64
Lease liabilities for certain operating leases	$ 58
Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		(25)	(5)
Accumulated Other Comprehensive Income (Loss) | DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects			(3)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		25	5
Retained Earnings | DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects			$ 3
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases		137
Lease liabilities for certain operating leases		130
Prepaid lease costs reclassified from Other assets, current and noncurrent		9
Deferred lease costs reclassified from Other liabilities, current and noncurrent		2
Accounting Standards Update 2016-02 | DTE Electric
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets for certain operating leases		74
Lease liabilities for certain operating leases		67
Accounting Standards Update 2018-02 | Accumulated Other Comprehensive Income (Loss)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		(25)
Accounting Standards Update 2018-02 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of income tax effects		$ 25