Retirement Benefits (Tables)

9 Months Ended

Jun. 30, 2019

Retirement Benefits [Abstract]

Components of Net Period Pension Costs

The components of net periodic pension costs for Versum’s defined benefit pension plans are as follows:

	Three Months Ended June 30,					Nine Months Ended June 30,
	2019		2018			2019			2018
(In millions)
Service cost	$	0.5	$	0.5		$	1.5		$	1.5
Interest cost	0.2		0.2			0.6			0.6
Expected return on assets	—		(0.1		)	(0.1		)	(0.1		)
Actuarial loss amortization	—		—			0.1			—
Net periodic pension cost	$	0.7	$	0.6		$	2.1		$	2.0

Defined Contribution Expense

The following table summarizes our defined contribution expense:

	Three Months Ended June 30,				Nine Months Ended June 30,
	2019		2018		2019		2018
(In millions)
Defined contribution expense	$	2.4	$	2.2	$	6.7	$	6.4