Retirement Benefits and Trusteed Assets (OPEB - Reconciliation of Obligations, Assets and Funded Status of Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in accumulated postretirement benefit obligation
Plan amendments	$ 4	$ 0
Amounts recognized in Regulatory assets
Regulatory assets	3,677	4,254
Other postretirement benefit plan
Change in accumulated postretirement benefit obligation
Projected/Accumulated postretirement benefit obligation, beginning of year	1,807	1,751
Service cost	30	26	$ 22
Interest cost	46	56	70
Plan amendments	1	0
Actuarial (gain) loss	(100)	54
Benefits paid	(82)	(80)
Projected/Accumulated postretirement benefit obligation, end of year	1,702	1,807	1,751
Change in plan assets
Plan assets at fair value, beginning of year	1,960	1,819
Actual return on plan assets	142	220
Benefits paid	(81)	(79)
Plan assets at fair value, end of year	2,021	1,960	1,819
Funded status	319	153
Amount recorded as:
Noncurrent assets	678	561
Current liabilities	(1)	(1)
Noncurrent liabilities	(358)	(407)
Defined benefit plans assets (liabilities)	319	153
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax
Net actuarial gain	(1)	(7)
Amounts recognized in Regulatory assets
Net actuarial loss	102	234
Prior service credit	(49)	(69)
Regulatory assets	53	165
DTE Electric
Amounts recognized in Regulatory assets
Regulatory assets	3,136	3,563
DTE Electric | Other postretirement benefit plan
Change in accumulated postretirement benefit obligation
Projected/Accumulated postretirement benefit obligation, beginning of year	1,369	1,337
Service cost	23	20	16
Interest cost	35	43	53
Plan amendments	0	0
Actuarial (gain) loss	(73)	31
Benefits paid	(61)	(62)
Projected/Accumulated postretirement benefit obligation, end of year	1,293	1,369	1,337
Change in plan assets
Plan assets at fair value, beginning of year	1,320	1,236
Actual return on plan assets	96	145
Benefits paid	(61)	(61)
Plan assets at fair value, end of year	1,355	1,320	$ 1,236
Funded status	62	(49)
Amount recorded as:
Noncurrent assets	402	335
Current liabilities	0	0
Noncurrent liabilities	(340)	(384)
Defined benefit plans assets (liabilities)	62	(49)
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax
Net actuarial gain	0	0
Amounts recognized in Regulatory assets
Net actuarial loss	61	156
Prior service credit	(34)	(48)
Regulatory assets	$ 27	$ 108