Retirement Benefits and Trusteed Assets (Tables)

9 Months Ended

Sep. 30, 2021

Retirement Benefits [Abstract]

Schedule of Net Periodic Benefit Costs (Credits)

The following tables detail the components of net periodic benefit costs (credits) for pension benefits and other postretirement benefits for DTE Energy:

	Pension Benefits				Other Postretirement Benefits
	Three Months Ended September 30,
	2021		2020		2021		2020
	(In millions)
Service cost	$	27	$	25	$	8	$	7
Interest cost	39		46		12		14
Expected return on plan assets	(84)		(84)		(33)		(32)
Amortization of:
Net actuarial loss	49		43		3		4
Prior service credit	—		—		(5)		(5)
Settlements	—		2		—		—
Net periodic benefit cost (credit)	$	31	$	32	$	(15)	$	(12)

	Pension Benefits				Other Postretirement Benefits
	Nine Months Ended September 30,
	2021		2020		2021		2020
	(In millions)
Service cost	$	81	$	74	$	23	$	20
Interest cost	118		139		35		42
Expected return on plan assets	(254)		(250)		(97)		(96)
Amortization of:
Net actuarial loss	147		129		10		12
Prior service credit	—		—		(15)		(15)
Settlements	—		2		—		—
Net periodic benefit cost (credit)	$	92	$	94	$	(44)	$	(37)

The following tables detail the components of net periodic benefit costs (credits) for other postretirement benefits for DTE Electric:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
	(In millions)
Service cost	$	6	$	5	$	17	$	15
Interest cost	8		11		25		32
Expected return on plan assets	(22)		(21)		(65)		(65)
Amortization of:
Net actuarial loss	3		2		9		8
Prior service credit	(3)		(3)		(10)		(10)
Net periodic benefit credit	$	(8)	$	(6)	$	(24)	$	(20)