Retirement Benefits and Trusteed Assets (Tables)

6 Months Ended

Jun. 30, 2016

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Schedule of Net Benefit Costs

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 June 30,	(In millions)
Service cost	$	23		$	24		$	7		$	8
Interest cost	55			53			20			21
Expected return on plan assets	(78		)	(74		)	(32		)	(32		)
Amortization of:
Net actuarial loss	41			52			8			11
Prior service credit	—			—			(29		)	(32		)
Net periodic benefit cost (credit)	$	41		$	55		$	(26	)	$	(24	)

	Pension Benefits						Other Postretirement Benefits
	2016			2015			2016			2015
Six Months Ended June 30,	(In millions)
Service cost	$	46		$	49		$	13		$	17
Interest cost	109			106			40			41
Expected return on plan assets	(155		)	(148		)	(64		)	(65		)
Amortization of:
Net actuarial loss	81			103			16			22
Prior service credit	—			—			(59		)	(63		)
Net periodic benefit cost (credit)	$	81		$	110		$	(54	)	$	(48	)

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 June 30,	(In millions)
Service cost	$	17		$	18		$	5		$	6
Interest cost	42			41			16			15
Expected return on plan assets	(55		)	(52		)	(22		)	(22		)
Amortization of:
Net actuarial loss	28			36			5			8
Prior service cost (credit)	1			1			(22		)	(23		)
Net periodic benefit cost (credit)	$	33		$	44		$	(18	)	$	(16	)

	Pension Benefits						Other Postretirement Benefits
	2016			2015			2016			2015
Six Months Ended June 30,	(In millions)
Service cost	$	35		$	38		$	10		$	13
Interest cost	83			81			31			31
Expected return on plan assets	(110		)	(105		)	(45		)	(45		)
Amortization of:
Net actuarial loss	57			74			11			16
Prior service cost (credit)	1			1			(44		)	(47		)
Net periodic benefit cost (credit)	$	66		$	89		$	(37	)	$	(32	)