Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2016

Retirement Plans [Abstract]

Net Periodic Benefit Cost

	Pension Benefits
	For the three months ended
	March 31,
	2016		2015
($ in millions)
Components of net periodic pension benefit cost
Service cost	$	13	$	13
Interest cost on projected benefit obligation		23		22
Expected return on plan assets		(28)		(32)
Amortization of unrecognized loss		11		7
Net periodic pension benefit cost	$	19	$	10

	Postretirement Benefits
	Other Than Pensions (OPEB)
	For the three months ended
	March 31,
	2016		2015
($ in millions)
Components of net periodic postretirement benefit cost
Service cost	$	3	$	5
Interest cost on projected benefit obligation		7		7
Amortization of prior service cost/(credit)		(2)		(1)
Amortization of unrecognized loss		-		3
Net periodic postretirement benefit cost	$	8	$	14