Pension and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2016

Pension Plan, Defined Benefit [Member]

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

Components of Pension Expense for Defined Benefit Pension Plan

	Three Months Ended June 30,						Six Months Ended June 30,
	2016			2015			2016			2015
	(in millions)
Interest cost on projected benefit obligation	$	12		$	12		$	24		$	24
Expected return on assets	(14		)	(17		)	(28		)	(33		)
Amortization of net actuarial loss	5			7			12			14
Administrative costs	1			1			2			2
Pension expense	$	4		$	3		$	10		$	7

Other Postretirement Benefit Plan, Defined Benefit [Member]

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

Components of Pension Expense for Defined Benefit Pension Plan

The components of our net postretirement benefit cost are as follows:

	Three Months Ended June 30,					Six Months Ended June 30,
	2016			2015		2016			2015
	(in millions)
Interest cost	$	1		$	2	$	2		$	3
Amortization of reduction in liability resulting from plan amendment	(1		)	—		(3		)	—
Net periodic postretirement benefit cost	$	—		$	2	$	(1	)	$	3