Retirement Benefits and Trusteed Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 24	$ 23
Interest cost	54	54
Expected return on plan assets	(78)	(77)
Amortization of net actuarial loss	43	40
Amortization of prior service cost (credit)	0	0
Net periodic benefit cost (credit)	43	40
Pension Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	18	18
Interest cost	41	41
Expected return on plan assets	(55)	(55)
Amortization of net actuarial loss	31	29
Amortization of prior service cost (credit)	0	0
Net periodic benefit cost (credit)	35	33
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	7	6
Interest cost	18	20
Expected return on plan assets	(33)	(32)
Amortization of net actuarial loss	3	8
Amortization of prior service cost (credit)	(3)	(30)
Net periodic benefit cost (credit)	(8)	(28)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	5	5
Interest cost	14	15
Expected return on plan assets	(23)	(23)
Amortization of net actuarial loss	2	6
Amortization of prior service cost (credit)	(2)	(22)
Net periodic benefit cost (credit)	$ (4)	$ (19)