Retirement Benefits and Trusteed Assets (Tables)

9 Months Ended

Sep. 30, 2016

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
	2016			2015			2016			2015
Three Months Ended September 30,	(In millions)
Service cost	$	23		$	27		$	7		$	8
Interest cost	55			52			20			20
Expected return on plan assets	(77		)	(74		)	(33		)	(33		)
Amortization of:
Net actuarial loss	43			51			6			10
Prior service credit	—			—			(29		)	(31		)
Net periodic benefit cost (credit)	$	44		$	56		$	(29	)	$	(26	)

	Pension Benefits						Other Postretirement Benefits
	2016			2015			2016			2015
Nine Months Ended September 30,	(In millions)
Service cost	$	69		$	76		$	20		$	25
Interest cost	164			158			60			61
Expected return on plan assets	(232		)	(222		)	(97		)	(98		)
Amortization of:
Net actuarial loss	124			154			22			32
Prior service credit	—			—			(88		)	(94		)
Net periodic benefit cost (credit)	$	125		$	166		$	(83	)	$	(74	)

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
	2016			2015			2016			2015
Three Months Ended September 30,	(In millions)
Service cost	$	18		$	21		$	5		$	6
Interest cost	42			39			15			15
Expected return on plan assets	(55		)	(53		)	(23		)	(23		)
Amortization of:
Net actuarial loss	31			36			4			8
Prior service credit	—			—			(22		)	(24		)
Net periodic benefit cost (credit)	$	36		$	43		$	(21	)	$	(18	)

	Pension Benefits						Other Postretirement Benefits
	2016			2015			2016			2015
Nine Months Ended September 30,	(In millions)
Service cost	$	53		$	59		$	15		$	19
Interest cost	125			120			46			46
Expected return on plan assets	(165		)	(158		)	(68		)	(68		)
Amortization of:
Net actuarial loss	88			110			15			24
Prior service cost (credit)	1			1			(66		)	(71		)
Net periodic benefit cost (credit)	$	102		$	132		$	(58	)	$	(50	)