Defined Benefit Postretirement Plans (Tables)

6 Months Ended

Jun. 30, 2018

Defined Benefit Postretirement Plans Disclosure [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

The following summarizes the components of net periodic benefit cost:

	Three Months Ended June 30,
	Pension Benefits						Other Benefits
(In millions)	2018			2017			2018			2017
Service cost	$	5		$	5		$	—		$	—
Interest cost	6			7			2			2
Expected return on plan assets	(8		)	(10		)	—			—
Amortization:
– prior service cost (credit)	(3		)	(2		)	(2		)	(1		)
– actuarial loss	3			2			1			—
Net settlement loss (a)	2			3			—			—
Net periodic benefit cost	$	5		$	5		$	1		$	1

	Six Months Ended June 30,
	Pension Benefits						Other Benefits
(In millions)	2018			2017			2018			2017
Service cost	$	9		$	11		$	1		$	1
Interest cost	13			15			4			4
Expected return on plan assets	(17		)	(22		)	—			—
Amortization:
– prior service cost (credit)	(5		)	(4		)	(4		)	(3		)
– actuarial loss	6			4			1			—
Net settlement loss (a)	6			17			—			—
Net periodic benefit cost	$	12		$	21		$	2		$	2

^(a)  Settlements are recognized as they occur, once it is probable that lump sum payments from a plan for a given year will exceed the plan’s total service and interest cost for that year.