Retirement Benefits and Trusteed Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 23	$ 27	$ 69	$ 76
Interest cost	55	52	164	158
Expected return on plan assets	(77)	(74)	(232)	(222)
Amortization of net actuarial loss	43	51	124	154
Amortization of prior service cost (credit)	0	0	0	0
Net periodic benefit cost (credit)	44	56	125	166
Pension Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	18	21	53	59
Interest cost	42	39	125	120
Expected return on plan assets	(55)	(53)	(165)	(158)
Amortization of net actuarial loss	31	36	88	110
Amortization of prior service cost (credit)	0	0	1	1
Net periodic benefit cost (credit)	36	43	102	132
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	7	8	20	25
Interest cost	20	20	60	61
Expected return on plan assets	(33)	(33)	(97)	(98)
Amortization of net actuarial loss	6	10	22	32
Amortization of prior service cost (credit)	(29)	(31)	(88)	(94)
Net periodic benefit cost (credit)	(29)	(26)	(83)	(74)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	5	6	15	19
Interest cost	15	15	46	46
Expected return on plan assets	(23)	(23)	(68)	(68)
Amortization of net actuarial loss	4	8	15	24
Amortization of prior service cost (credit)	(22)	(24)	(66)	(71)
Net periodic benefit cost (credit)	$ (21)	$ (18)	$ (58)	$ (50)