Pension and Other Postretirement Benefits (Tables)

3 Months Ended

Jul. 31, 2020

Retirement Benefits [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

The following table shows the components of the net cost of pension and other postretirement benefits recognized for our U.S. benefit plans. Information about similar international plans is not presented due to immateriality.

	Three Months Ended
	July 31,
(Dollars in millions)	2019			2020
Pension Benefits:
Service cost	$	6		$	7
Interest cost	8			6
Expected return on plan assets	(12		)	(12		)
Amortization of net actuarial loss	5			7
Net cost	$	7		$	8
Other Postretirement Benefits:
Interest cost	$	1		$	1
Amortization of prior service cost (credit)	(1		)	(1		)
Net cost	$	—		$	—