Pension and Other Postretirement Benefits (Tables)

9 Months Ended

Jan. 31, 2017

Compensation and Retirement Disclosure [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

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

	Three Months Ended						Nine Months Ended
	January 31,						January 31,
(Dollars in millions)	2016			2017			2016			2017
Pension Benefits:
Service cost	$	6		$	6		$	19		$	19
Interest cost	9			9			26			26
Expected return on plan assets	(10		)	(10		)	(30		)	(31		)
Amortization of:
Prior service cost (credit)	—			—			1			1
Net actuarial loss	7			6			21			19
Settlement loss	$	—		$	1		$	—		$	1
Net cost	$	12		$	12		$	37		$	35
Other Postretirement Benefits:
Service cost	$	—		$	—		$	1		$	1
Interest cost	1			1			2			2
Amortization of:
Prior service cost (credit)	(1		)	(1		)	(2		)	(2		)
Net actuarial loss	—			—			1			—
Net cost	$	—		$	—		$	2		$	1