Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	$ 4	$ (44)
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	(1)	0
Total gains (losses):
Included in earnings	44	(1)
Recorded in/Change in fair value recorded in Regulatory liabilities	(2)	(3)
Purchases, issuances, and settlements
Settlements	(21)	15
Net Assets (Liabilities) as of end of period	24	(33)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2020 and 2019 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	40	(6)
DTE Electric
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	3	6
Total gains (losses):
Recorded in/Change in fair value recorded in Regulatory liabilities	(2)	(3)
Purchases, issuances, and settlements
Settlements	0	(1)
Net Assets (Liabilities) as of end of period	1	2
The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at March 31, 2020 and 2019 and reflected in DTE Electric's Consolidated Statements of Financial Position	0	0
Natural gas
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	(15)	(49)
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	(1)	0
Total gains (losses):
Included in earnings	24	31
Recorded in/Change in fair value recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements
Settlements	0	8
Net Assets (Liabilities) as of end of period	8	(10)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2020 and 2019 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	19	16
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	16	(2)
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	0	0
Total gains (losses):
Included in earnings	20	(31)
Recorded in/Change in fair value recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements
Settlements	(21)	8
Net Assets (Liabilities) as of end of period	15	(25)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2020 and 2019 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	21	(21)
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	3	7
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	0	0
Total gains (losses):
Included in earnings	0	(1)
Recorded in/Change in fair value recorded in Regulatory liabilities	(2)	(3)
Purchases, issuances, and settlements
Settlements	0	(1)
Net Assets (Liabilities) as of end of period	1	2
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2020 and 2019 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	$ 0	$ (1)