Retirement Plans (Tables)

3 Months Ended

Mar. 31, 2020

Retirement Plans [Abstract]

Net Periodic Benefit Cost

	Pension Benefits
	For the three months ended
	March 31,
($ in millions)	2020		2019
Components of total pension benefit cost
Service cost	$	25	$	21
Interest cost on projected benefit obligation		30		33
Expected return on plan assets		(50)		(43)
Amortization of unrecognized loss		17		14
Net periodic pension benefit cost		22		25
Pension settlement costs		103		-
Total pension benefit cost	$	125	$	25
	Postretirement Benefits
	For the three months ended
	March 31,
($ in millions)	2020		2019
Components of net periodic postretirement benefit cost
Service cost	$	5	$	5
Interest cost on projected benefit obligation		8		10
Amortization of prior service cost (credit)		(8)		(1)
Amortization of unrecognized (gain) loss		2		(2)
Net periodic postretirement benefit cost	$	7	$	12