Retirement Benefits and Trusteed Assets (Tables)

3 Months Ended

Mar. 31, 2018

Defined Benefit Plan [Abstract]

Schedule of Net Periodic Benefit Costs (Credits)

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

	Other Postretirement Benefits
	2018			2017
Three Months Ended March 31,	(In millions)
Service cost	$	5		$	5
Interest cost	13			14
Expected return on plan assets	(24		)	(23		)
Amortization of:
Net actuarial loss	2			2
Prior service credit	—			(2		)
Net periodic benefit credit	$	(4	)	$	(4	)

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
	2018			2017			2018			2017
Three Months Ended March 31,	(In millions)
Service cost	$	25		$	24		$	7		$	7
Interest cost	50			54			17			18
Expected return on plan assets	(82		)	(78		)	(36		)	(33		)
Amortization of:
Net actuarial loss	44			43			3			3
Prior service credit	—			—			—			(3		)
Net periodic benefit cost (credit)	$	37		$	43		$	(9	)	$	(8	)

Schedule of Defined Benefit Plans Disclosures

During 2018, DTE Energy contributed the following amounts of DTE Energy common stock to the DTE Energy Company Affiliates Employee Benefit Plans Master Trust:

Date	Number of Shares	Price per Share	Amount
			(In millions)
March 7, 2018	1,751,401	$99.92	$	175