Compensation Related Costs, Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2020

Retirement Benefits [Abstract]

Net Periodic Benefit Cost for All Significant Plans

The following table provides the components of the Corporation's net periodic benefit cost for all significant plans:

Net Periodic Benefit Cost for All Significant Plans	Three Months Ended
In millions	Mar 31, 2020		Mar 31, 2019
Defined Benefit Pension Plans:
Service cost	$	9	$	9
Interest cost	28		36
Expected return on plan assets	(50)		(53)
Amortization of net loss	27		21
Net periodic benefit cost	$	14	$	13
Other Postretirement Benefit Plan:
Interest cost	$	1	$	2
Amortization of net gain	(1)		(2)
Net periodic benefit cost	$	—	$	—