Pension and Other Postretirement Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2017

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				Six Months Ended				Three Months Ended				Six Months Ended
	June 30,				June 30,				June 30,				June 30,
(In millions)	2017		2016		2017		2016		2017		2016		2017		2016
Service cost	$	1	$	1	$	1	$	1	$	-	$	-	$	-	$	-
Interest cost		45		49		93		99		2		2		5		5
Expected long-term return on plan assets		(64)		(62)		(129)		(124)		-		-		-		-
Amortization of:
Net loss from past experience		17		16		33		33		-		-		-		-
Prior service cost		-		-		-		-		-		-		(1)		(1)
Settlement loss		-		-		6		-		-		-		-		-
Net cost	$	(1)	$	4	$	4	$	9	$	2	$	2	$	4	$	4