Employee Benefit Plans (Tables)

6 Months Ended

Mar. 31, 2020

Retirement Benefits [Abstract]

Components of Pension and Other Postretirement Benefit Income

The following table summarizes the components of pension and other postretirement benefit (income) cost:

					Other postretirement benefits
	Pension benefits
(In millions)	2020		2019		2020		2019
Three months ended March 31
Service cost	$	—	$	1	$	—	$	—
Interest cost	15		20		1		—
Expected return on plan assets	(22)		(20)		—		—
Amortization of prior service credit	—		—		(3)		(3)
Net periodic benefit (income) cost	$	(7)	$	1	$	(2)	$	(3)
Six months ended March 31
Service cost	$	1	$	1	$	—	$	—
Interest cost	31		40		1		1
Expected return on plan assets	(44)		(40)		—		—
Amortization of prior service credit	—		—		(6)		(6)
Net periodic benefit (income) cost	$	(12)	$	1	$	(5)	$	(5)