Retirement Benefits and Trusteed Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 24	$ 21	$ 49	$ 42
Interest cost	47	54	93	109
Expected return on plan assets	(83)	(81)	(166)	(162)
Amortization of net actuarial loss	43	34	86	66
Amortization of prior service credit	0	0	0	0
Net periodic benefit cost (credit)	31	28	62	55
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	6	13	11
Interest cost	14	17	28	35
Expected return on plan assets	(32)	(31)	(64)	(62)
Amortization of net actuarial loss	3	3	8	6
Amortization of prior service credit	(5)	(2)	(10)	(4)
Net periodic benefit cost (credit)	(13)	(7)	(25)	(14)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	4	10	8
Interest cost	10	14	21	27
Expected return on plan assets	(22)	(21)	(44)	(42)
Amortization of net actuarial loss	3	1	6	2
Amortization of prior service credit	(3)	(3)	(7)	(4)
Net periodic benefit cost (credit)	$ (7)	$ (5)	$ (14)	$ (9)