Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	$ (57)	$ (12)	$ (4)	$ 24
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	(1)	0
Total gains (losses):
Included in earnings	(22)	14	(101)	(13)
Recorded in Regulatory liabilities	6	13	4	11
Purchases, issuances, and settlements:
Purchases	1	1	1	2
Settlements	3	(20)	32	(28)
Net Assets (Liabilities) as of end of period	(69)	(4)	(69)	(4)
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 June 30, 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	(43)	(4)	(119)	(102)
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	1	1	3	3
Total gains (losses):
Recorded in Regulatory liabilities	6	13	4	11
Purchases, issuances, and settlements:
Settlements	(3)	(9)	(3)	(9)
Net Assets (Liabilities) as of end of period	4	5	4	5
The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at June 30, 2016 and 2015 and reflected in DTE Electric's Consolidated Statements of Financial Position	4	5	4	5
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	(34)	0	(5)	30
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	(1)	0
Total gains (losses):
Included in earnings	(36)	(5)	(56)	(35)
Recorded in Regulatory liabilities	0	0	0	0
Purchases, issuances, and settlements:
Purchases	0	0	0	0
Settlements	8	(3)	0	(3)
Net Assets (Liabilities) as of end of period	(62)	(8)	(62)	(8)
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 June 30, 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	(41)	(20)	(113)	(112)
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)	(7)	6	(5)
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	0	0
Total gains (losses):
Included in earnings	12	18	(46)	24
Recorded in Regulatory liabilities	0	0	0	0
Purchases, issuances, and settlements:
Purchases	1	1	1	2
Settlements	(3)	(9)	33	(18)
Net Assets (Liabilities) as of end of period	(6)	3	(6)	3
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 June 30, 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	(4)	15	(7)	11
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	(7)	(5)	(5)	(1)
Transfers into Level 3 from Level 2	0	0	0	0
Transfers from Level 3 into Level 2	0	0	0	0
Total gains (losses):
Included in earnings	2	1	1	(2)
Recorded in Regulatory liabilities	6	13	4	11
Purchases, issuances, and settlements:
Purchases	0	0	0	0
Settlements	(2)	(8)	(1)	(7)
Net Assets (Liabilities) as of end of period	(1)	1	(1)	1
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 June 30, 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	$ 2	$ 1	$ 1	$ (1)