Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	$ (4)	$ 24
Transfers into Level 3 from Level 2	0	(1)
Transfers from Level 3 into Level 2	(1)	0
Total gains (losses):
Included in earnings	(79)	(24)
Recorded in Regulatory assets	(2)	(2)
Purchases, issuances, and settlements:
Settlements	29	(9)
Net Assets (Liabilities) as of end of period	(57)	(12)
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, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(76)	(96)
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	3
Total gains (losses):
Recorded in Regulatory assets	(2)	(2)
Purchases, issuances, and settlements:
Settlements	0	0
Net Assets (Liabilities) as of end of period	1	1
The amount of total gains (losses) included in Regulatory assets attributed to the change in unrealized gains (losses) related to assets held at March 31, 2016 and 2015 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	(5)	30
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	(1)	0
Total gains (losses):
Included in earnings	(20)	(29)
Recorded in Regulatory assets	0	0
Purchases, issuances, and settlements:
Settlements	(8)	(1)
Net Assets (Liabilities) as of end of period	(34)	0
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, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(72)	(91)
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	6	(5)
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	0	0
Total gains (losses):
Included in earnings	(58)	7
Recorded in Regulatory assets	0	0
Purchases, issuances, and settlements:
Settlements	36	(9)
Net Assets (Liabilities) as of end of period	(16)	(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 March 31, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(3)	(3)
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	(5)	(1)
Transfers into Level 3 from Level 2	0	(1)
Transfers from Level 3 into Level 2	0	0
Total gains (losses):
Included in earnings	(1)	(2)
Recorded in Regulatory assets	(2)	(2)
Purchases, issuances, and settlements:
Settlements	1	1
Net Assets (Liabilities) as of end of period	(7)	(5)
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, 2016 and 2015 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)	$ (2)