Pension and Other Postretirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2018

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Components of net defined benefit plan costs

	Pension Benefits				Other Postretirement Benefits
	Three Months Ended				Three Months Ended
	March 31,				March 31,
(In millions)	2018		2017		2018		2017
Service cost	$	1	$	-	$		$	-
Interest cost		42		48		2		3
Expected long-term return on plan assets		(64)		(65)				-
Amortization of:
Net loss from past experience		17		16				-
Prior service cost				-		-		(1)
Settlement loss				6				-
Net cost	$	(4)	$	5	$	2	$	2