Retirement Benefits and Trusteed Assets (Tables)

3 Months Ended

Mar. 31, 2017

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [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
	2017			2016			2017			2016
Three Months Ended March 31,	(In millions)
Service cost	$	24		$	23		$	7		$	6
Interest cost	54			54			18			20
Expected return on plan assets	(78		)	(77		)	(33		)	(32		)
Amortization of:
Net actuarial loss	43			40			3			8
Prior service credit	—			—			(3		)	(30		)
Net periodic benefit cost (credit)	$	43		$	40		$	(8	)	$	(28	)

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

	Pension Benefits						Other Postretirement Benefits
	2017			2016			2017			2016
Three Months Ended March 31,	(In millions)
Service cost	$	18		$	18		$	5		$	5
Interest cost	41			41			14			15
Expected return on plan assets	(55		)	(55		)	(23		)	(23		)
Amortization of:
Net actuarial loss	31			29			2			6
Prior service credit	—			—			(2		)	(22		)
Net periodic benefit cost (credit)	$	35		$	33		$	(4	)	$	(19	)