Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	$ (44)	$ (9)
Transfers from Level 3 into Level 2	0	(3)
Total gains (losses)
Included in earnings	91	(116)
Recorded in Regulatory liabilities	2	9
Purchases, issuances, and settlements:
Settlements	(45)	75
Net Assets (Liabilities) as of December 31	4	(44)
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 December 31, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	20	(120)
Natural Gas
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	(49)	(29)
Transfers from Level 3 into Level 2	0	(3)
Total gains (losses)
Included in earnings	15	(146)
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements:
Settlements	19	129
Net Assets (Liabilities) as of December 31	(15)	(49)
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 December 31, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(1)	(119)
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	(2)	12
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	77	29
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements:
Settlements	(59)	(43)
Net Assets (Liabilities) as of December 31	16	(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 December 31, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	59	15
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	7	8
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	(1)	1
Recorded in Regulatory liabilities	2	9
Purchases, issuances, and settlements:
Settlements	(5)	(11)
Net Assets (Liabilities) as of December 31	3	7
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 December 31, 2019 and 2018 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(38)	(16)
DTE Electric
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	6	9
Total gains (losses)
Recorded in Regulatory liabilities	2	9
Purchases, issuances, and settlements:
Settlements	(5)	(12)
Net Assets (Liabilities) as of December 31	3	6
The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31, 2019 and 2018 and reflected in DTE Electric's Consolidated Statements of Financial Position	$ 3	$ 6