Retirement Benefits and Trusteed Assets (OPEB - Reconciliation of Obligations, Assets and Funded Status of Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Amounts recognized in Regulatory assets(a)
Regulatory assets	$ 3,913	$ 3,724
Other postretirement benefit plan
Change in accumulated postretirement benefit obligation
Projected benefit obligation, beginning of year	1,846	2,044
Service cost	27	34	$ 34
Interest cost	80	81	89
Actuarial (gain) loss	(75)	(224)
Benefits paid	(83)	(89)
Projected benefit obligation, end of year	1,795	1,846	2,044
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	1,617	1,528
Actual return on plan assets	122	(25)
Company contributions	20	199
Benefits paid	(1)	(85)
Plan assets at fair value, end of year	1,758	1,617	1,528
Funded status, end of year	(37)	(229)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent assets	0	0
Current liabilities	(1)	(1)
Noncurrent liabilities	(36)	(228)
Defined benefit plans liabilities	(37)	(229)
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax
Net actuarial loss	12	24
Prior service cost (credit)	0	(2)
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax	12	22
Amounts recognized in Regulatory assets(a)
Net actuarial loss	300	387
Prior service credit	(14)	(131)
Regulatory assets	286	256
DTE Electric
Amounts recognized in Regulatory assets(a)
Regulatory assets	3,149	2,986
DTE Electric | Other postretirement benefit plan
Change in accumulated postretirement benefit obligation
Projected benefit obligation, beginning of year	1,414	1,558
Service cost	20	25	26
Interest cost	61	62	68
Actuarial (gain) loss	(62)	(166)
Benefits paid	(60)	(65)
Projected benefit obligation, end of year	1,373	1,414	1,558
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Plan assets at fair value, beginning of year	1,131	1,038
Actual return on plan assets	87	(19)
Company contributions	0	175
Benefits paid	0	(63)
Plan assets at fair value, end of year	1,218	1,131	$ 1,038
Funded status, end of year	(155)	(283)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent assets	114	24
Current liabilities	0	0
Noncurrent liabilities	(269)	(307)
Defined benefit plans liabilities	(155)	(283)
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax
Net actuarial loss	0	0
Prior service cost (credit)	0	0
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax	0	0
Amounts recognized in Regulatory assets(a)
Net actuarial loss	217	297
Prior service credit	(10)	(99)
Regulatory assets	$ 207	$ 198